Document reminders, offline PWA, and fix missing Celery Beat in deploy guide

API.md: document the reminder/due_soon/overdue notification schedule
(including the due_time-aware is_overdue fix and the 1-hour overdue
delay) and how default_reminder_minutes/reminder_at interact.

README.md: add Offline Support (PWA) and Notifications & Reminders to
the feature list - both were fully functional but never listed. Also
fixes a real gap in the manual systemd deployment guide: it only set
up the Celery worker, never Celery Beat, so the daily digest, recurring
task safety net, and now reminders would never fire for anyone
following that guide.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -24,6 +24,7 @@ stack.env
 # IDE
 .idea/
 .vscode/
+.codex
 *.swp
 *.swo
 
@@ -41,3 +42,10 @@ htmlcov/
 
 # Firebase credentials
 *firebase*.json
+
+# Local Node artifacts used for tooling in this repo
+package.json
+package-lock.json
+
+# Local AI assistant instructions (not for the repo)
+CLAUDE.md

Dockerfile

@@ -28,6 +28,7 @@ FROM python:3.12-slim-bookworm
 RUN apt-get update && apt-get install -y --no-install-recommends \
     postgresql-client \
     curl \
+    procps \
     && rm -rf /var/lib/apt/lists/*
 
 # Create django user (non-root for security)

PORTAINER_DEPLOYMENT.md

@@ -8,7 +8,7 @@ This guide will walk you through deploying the KeepItGoing server to your Docker
 
 - Portainer installed and accessible
 - Access to your Docker server via Portainer
-- Git repository: `https://git.firebugit.com/Firebug_IT/KeepItGoingServer.git`
+- Git repository: `https://git.darksingularity.org/DarkSingularity/KeepItGoingServer.git`
 - Git credentials configured in Portainer (or repository is public)
 
 ## Deployment Steps
@@ -31,7 +31,7 @@ This guide will walk you through deploying the KeepItGoing server to your Docker
 
    **Repository URL:**
    ```
-   https://git.firebugit.com/Firebug_IT/KeepItGoingServer.git
+   https://git.darksingularity.org/DarkSingularity/KeepItGoingServer.git
    ```
 
    **Repository reference:** `refs/heads/main`
@@ -40,17 +40,16 @@ This guide will walk you through deploying the KeepItGoing server to your Docker
 
    **Authentication:**
    - If repository is private, enable authentication
-   - Username: `keith@firebugit.com`
-   - Password: (your Git password)
-   - Or use an access token if available
+   - Username: your Gitea account username
+   - Password: a Gitea access token (recommended over your account password)
 
 ### Step 4: Configure Environment Variables
 
-Scroll down to the **Environment variables** section and paste the following:
+Scroll down to the **Environment variables** section and paste the following, replacing every `<...>` placeholder with the actual value from your password manager / secrets store (never commit real values to this file):
 
 ```env
 # Django Core Settings
-SECRET_KEY=Zfb$!,3Gm\b,x~:a)9@k*Gun.#F{ju3dH-G8aWp4R"&NQ{1x>14v#)EbhpB*XMWD
+SECRET_KEY=<django-secret-key>
 DEBUG=False
 ALLOWED_HOSTS=keepitgoing.app,www.keepitgoing.app,localhost
 CSRF_TRUSTED_ORIGINS=https://keepitgoing.app,https://www.keepitgoing.app
@@ -59,8 +58,8 @@ SITE_DOMAIN=keepitgoing.app
 # Database Configuration
 DB_NAME=keepitgoing
 DB_USER=keepitgoing
-DB_PASSWORD=6SWh6Pz01hBFGNzWM0Pszz2moluqxyv7
-DB_ROOT_PASSWORD=l7xF4j20HxqE2ZGNDR2FIoCCYwb6tDMq
+DB_PASSWORD=<db-password>
+DB_ROOT_PASSWORD=<db-root-password>
 DB_HOST=mariadb
 DB_PORT=3306
 
@@ -73,13 +72,18 @@ EMAIL_HOST=smtp.dreamhost.com
 EMAIL_PORT=587
 EMAIL_USE_TLS=True
 EMAIL_HOST_USER=kig@keepitgoing.app
-EMAIL_HOST_PASSWORD=Frankenmonster1!
+EMAIL_HOST_PASSWORD=<email-host-password>
 DEFAULT_FROM_EMAIL=KeepItGoing <kig@keepitgoing.app>
 SERVER_EMAIL=kig@keepitgoing.app
 
 # Email Verification
 EMAIL_VERIFICATION_TOKEN_EXPIRY_HOURS=24
 
+# Web Push (generate with `python manage.py generate_vapid_keys`)
+VAPID_PUBLIC_KEY=<vapid-public-key>
+VAPID_PRIVATE_KEY=<vapid-private-key>
+VAPID_ADMIN_EMAIL=<admin-contact-email>
+
 # CORS Configuration
 CORS_ALLOWED_ORIGINS=https://keepitgoing.app,https://www.keepitgoing.app
 
@@ -210,7 +214,7 @@ To backup the database:
    ```bash
    mysqldump -u root -p keepitgoing > /tmp/backup.sql
    ```
-4. Enter root password: `l7xF4j20HxqE2ZGNDR2FIoCCYwb6tDMq`
+4. Enter the `DB_ROOT_PASSWORD` value from your Portainer stack environment variables
 5. Use **File browser** to download `/tmp/backup.sql`
 
 ### Scaling

README.md

@@ -9,7 +9,7 @@ A powerful Django-based task management system with time tracking, tag organizat
 - **Priority Levels**: Low, Medium, High, and Urgent
 - **Status Tracking**: Pending, In Progress, Completed, Cancelled
 - **Due Dates & Times**: Set specific due dates and times for tasks
-- **Recurrence**: Daily, Weekly, Bi-weekly, Monthly, Yearly, and Custom patterns
+- **Recurrence**: Daily, Weekly, Bi-weekly, Monthly, Yearly, plus Custom RRULE patterns (e.g. every other Wednesday, every second Tuesday, every 15th of the month)
 
 ### Organization
 - **Tag-Based System**: Organize tasks with multiple colored tags
@@ -25,8 +25,8 @@ A powerful Django-based task management system with time tracking, tag organizat
 
 ### User Management
 - **Multi-user Support**: Full authentication and user management
-- **Email Verification**: Secure email verification for new user registrations
-- **Admin Approval**: Optional admin approval workflow for new users
+- **Email Verification**: Secure email verification for admin-created or self-registered accounts
+- **Admin Approval**: Optional approval workflow for new users
 - **User Profiles**: Customizable profiles with timezone and notification preferences
 - **Password Management**: Secure password change functionality
 
@@ -43,6 +43,16 @@ A powerful Django-based task management system with time tracking, tag organizat
 - **Real-time Updates**: Task changes sync across devices
 - **Conflict Resolution**: Handles offline changes and syncing
 
+### Offline Support (PWA)
+- **Installable Web App**: Add to home screen with an offline-capable service worker
+- **Full Offline Task Management**: Create, edit, complete tasks, manage subtasks and tags, and track time while offline
+- **Automatic Sync**: Offline changes queue locally and sync automatically once back online
+
+### Notifications & Reminders
+- **Daily Digest**: Morning email summarizing tasks due today and overdue tasks
+- **Per-Task Reminders**: Automatic "before due", "due now", and "overdue" notifications, timed per task
+- **Multi-Channel Delivery**: Email, push, or both, per user
+
 ## Tech Stack
 
 - **Backend**: Django 5.x, Django REST Framework
@@ -119,6 +129,15 @@ Set via environment variable:
 export DJANGO_SETTINGS_MODULE=config.settings.development
 ```
 
+### Registration Control
+
+Self-registration is controlled with `ALLOW_SELF_REGISTRATION`.
+
+- `ALLOW_SELF_REGISTRATION=False` disables public signup and requires an administrator to create accounts
+- `ALLOW_SELF_REGISTRATION=True` enables the `/register/` page and `/api/users/register/` endpoint
+
+If the variable is omitted, self-registration is disabled by default.
+
 ### Database Configuration
 
 The application supports multiple database backends. Choose the one that fits your needs.
@@ -821,7 +840,9 @@ sudo systemctl start keepitgoing
 sudo systemctl status keepitgoing
 ```
 
-#### Step 6: Celery Service (Optional, for background tasks)
+#### Step 6: Celery Services (Worker + Beat)
+
+Both services are required - the worker executes tasks, Beat is the scheduler that queues the daily digest, recurring task safety net, and per-task reminders on their configured schedules (see `config/celery.py`).
 
 ```bash
 sudo nano /etc/systemd/system/keepitgoing-celery.service
@@ -852,6 +873,37 @@ sudo systemctl enable keepitgoing-celery
 sudo systemctl start keepitgoing-celery
 ```
 
+Beat runs as its own separate service:
+
+```bash
+sudo nano /etc/systemd/system/keepitgoing-celerybeat.service
+```
+
+```ini
+[Unit]
+Description=KeepItGoing Celery Beat
+After=network.target redis.service
+
+[Service]
+Type=simple
+User=keepitgoing
+Group=keepitgoing
+WorkingDirectory=/home/keepitgoing/KeepItGoingServer
+Environment="PATH=/home/keepitgoing/KeepItGoingServer/venv/bin"
+Environment="DJANGO_SETTINGS_MODULE=config.settings.production"
+EnvironmentFile=/home/keepitgoing/KeepItGoingServer/.env
+ExecStart=/home/keepitgoing/KeepItGoingServer/venv/bin/celery -A config beat -l info
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable and start:
+```bash
+sudo systemctl enable keepitgoing-celerybeat
+sudo systemctl start keepitgoing-celerybeat
+```
+
 #### Step 7: Nginx Configuration
 
 ```bash
@@ -955,11 +1007,15 @@ sudo ufw status
 # Log in to the web interface at https://tasks.firebugit.com/admin
 # Use the superuser credentials created in Step 3
 
-# When new users register:
+# If ALLOW_SELF_REGISTRATION=True and new users register:
 # 1. They receive verification email
 # 2. After clicking verification link, you receive admin notification
 # 3. Go to Admin > Users > select user(s) > Actions > "Approve selected users"
 # 4. User receives approval email and can now log in
+#
+# If ALLOW_SELF_REGISTRATION=False:
+# 1. Create users through Django admin or management commands
+# 2. Mark them verified/approved as needed for your onboarding flow
 ```
 
 ### Production Checklist
@@ -994,7 +1050,8 @@ Complete this checklist before going live:
 - [ ] Run `python manage.py migrate` to apply all migrations
 - [ ] Run `python manage.py collectstatic` for static files
 - [ ] Create superuser account for admin access
-- [ ] Test user registration and email verification flow
+- [ ] Confirm `ALLOW_SELF_REGISTRATION` is set correctly for production
+- [ ] Test account onboarding flow (admin-created users or public registration)
 - [ ] Test admin approval workflow
 - [ ] Configure `SITE_DOMAIN` to your production domain
 - [ ] Set appropriate `EMAIL_VERIFICATION_TOKEN_EXPIRY_HOURS`
@@ -1002,8 +1059,8 @@ Complete this checklist before going live:
 **Services:**
 - [ ] Set up Gunicorn systemd service
 - [ ] Configure nginx as reverse proxy
-- [ ] Set up Redis for Celery (if using background tasks)
-- [ ] Configure Celery systemd service (if needed)
+- [ ] Set up Redis for Celery (required for the daily digest, recurring tasks, and reminders)
+- [ ] Configure both the Celery worker and Celery Beat systemd services - Beat is what fires scheduled tasks, the worker alone won't
 - [ ] Verify all services start on boot
 
 **Monitoring & Logging:**

config/celery.py

@@ -22,13 +22,17 @@ app.autodiscover_tasks()
 
 # Celery Beat schedule for periodic tasks
 app.conf.beat_schedule = {
-    'send-due-reminders': {
-        'task': 'notifications.tasks.send_due_reminders',
-        'schedule': crontab(minute='*/5'),  # Every 5 minutes
+    'send-daily-task-email': {
+        'task': 'notifications.tasks.send_daily_task_email',
+        'schedule': crontab(minute=0),  # Every hour on the hour
     },
-    'check-overdue-tasks': {
-        'task': 'notifications.tasks.check_overdue_tasks',
-        'schedule': crontab(hour=8, minute=0),  # Daily at 8 AM
+    'process-recurring-tasks': {
+        'task': 'notifications.tasks.process_recurring_tasks',
+        'schedule': crontab(hour=0, minute=0),  # Daily at midnight
+    },
+    'send-scheduled-reminders': {
+        'task': 'notifications.tasks.send_scheduled_reminders',
+        'schedule': crontab(minute='*/5'),  # Every 5 minutes - these are time-sensitive
     },
 }
 

config/settings/base.py

@@ -44,6 +44,7 @@ MIDDLEWARE = [
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
     'django.middleware.clickjacking.XFrameOptionsMiddleware',
+    'tasks.middleware.AllowMobileAppFramingMiddleware',  # Allow mobile app iframe embedding
 ]
 
 ROOT_URLCONF = 'config.urls'
@@ -162,6 +163,7 @@ CELERY_RESULT_SERIALIZER = 'json'
 SAAS_MODE = os.environ.get('SAAS_MODE', 'False').lower() == 'true'
 BILLING_ENABLED = SAAS_MODE
 USAGE_LIMITS_ENABLED = SAAS_MODE
+ALLOW_SELF_REGISTRATION = os.environ.get('ALLOW_SELF_REGISTRATION', 'False').lower() == 'true'
 
 # Login settings
 LOGIN_URL = '/login/'
@@ -173,3 +175,8 @@ EMAIL_VERIFICATION_TOKEN_EXPIRY_HOURS = int(
     os.environ.get('EMAIL_VERIFICATION_TOKEN_EXPIRY_HOURS', 24)
 )
 SITE_DOMAIN = os.environ.get('SITE_DOMAIN', 'localhost:8000')
+
+# Web Push (VAPID)
+VAPID_PUBLIC_KEY = os.environ.get('VAPID_PUBLIC_KEY', '')
+VAPID_PRIVATE_KEY = os.environ.get('VAPID_PRIVATE_KEY', '')
+VAPID_ADMIN_EMAIL = os.environ.get('VAPID_ADMIN_EMAIL', '')

config/urls.py

@@ -6,17 +6,28 @@ from django.contrib import admin
 from django.urls import path, include
 from django.conf import settings
 from django.conf.urls.static import static
+from django.views.generic import TemplateView
 
 from users.urls import api_urlpatterns as users_api_urls, web_urlpatterns as users_web_urls
 from tasks.urls import api_urlpatterns as tasks_api_urls, web_urlpatterns as tasks_web_urls
 from sync.urls import api_urlpatterns as sync_api_urls
 from notifications.urls import api_urlpatterns as notifications_api_urls
-from .views import api_root
+from tasks.views_debug import debug_user_agent
+from .views import api_root, manifest_webmanifest, service_worker
 
 urlpatterns = [
     # Admin
     path('admin/', admin.site.urls),
 
+    # PWA
+    path('manifest.webmanifest', manifest_webmanifest, name='manifest'),
+    path('sw.js', service_worker, name='service-worker'),
+    path('offline/', TemplateView.as_view(template_name='offline.html'), name='offline'),
+    path('offline/tasks/', TemplateView.as_view(template_name='offline_tasks.html'), name='offline-tasks'),
+
+    # Debug endpoint (remove in production)
+    path('debug/user-agent/', debug_user_agent, name='debug-user-agent'),
+
     # API root
     path('api/', api_root, name='api-root'),
 

config/views.py

@@ -3,6 +3,23 @@ API root views for KeepItGoing.
 """
 
 from django.http import JsonResponse
+from django.shortcuts import render
+
+
+def manifest_webmanifest(request):
+    """Serve the PWA web app manifest, rendered so icon URLs pick up static hashing."""
+    return render(request, 'manifest.webmanifest', content_type='application/manifest+json')
+
+
+def service_worker(request):
+    """
+    Serve the service worker script from the site root so its default scope
+    covers the whole app (a service worker can only control paths at or
+    below where it's served from).
+    """
+    response = render(request, 'sw.js', content_type='application/javascript')
+    response['Cache-Control'] = 'no-cache'
+    return response
 
 
 def api_root(request):

docker-compose.yml

@@ -46,7 +46,7 @@ services:
   # =================================================================
   web:
     build:
-      context: .
+      context: https://git.darksingularity.org/DarkSingularity/KeepItGoingServer.git#main
       dockerfile: Dockerfile
     container_name: keepitgoing-web
     restart: unless-stopped
@@ -74,6 +74,10 @@ services:
       EMAIL_HOST_PASSWORD: ${EMAIL_HOST_PASSWORD:-}
       EMAIL_USE_TLS: ${EMAIL_USE_TLS:-True}
       DEFAULT_FROM_EMAIL: ${DEFAULT_FROM_EMAIL:-noreply@localhost}
+      SITE_DOMAIN: ${SITE_DOMAIN:-localhost:8000}
+      VAPID_PUBLIC_KEY: ${VAPID_PUBLIC_KEY:-}
+      VAPID_PRIVATE_KEY: ${VAPID_PRIVATE_KEY:-}
+      VAPID_ADMIN_EMAIL: ${VAPID_ADMIN_EMAIL:-}
 
       # Gunicorn
       GUNICORN_WORKERS: ${GUNICORN_WORKERS:-3}
@@ -103,7 +107,7 @@ services:
   # =================================================================
   celery-worker:
     build:
-      context: .
+      context: https://git.darksingularity.org/DarkSingularity/KeepItGoingServer.git#main
       dockerfile: Dockerfile
     container_name: keepitgoing-celery-worker
     restart: unless-stopped
@@ -112,6 +116,16 @@ services:
       SECRET_KEY: ${SECRET_KEY}
       DATABASE_URL: postgresql://${DB_USER:-keepitgoing}:${DB_PASSWORD}@postgres:5432/${DB_NAME:-keepitgoing}
       REDIS_URL: redis://redis:6379/0
+      EMAIL_HOST: ${EMAIL_HOST:-}
+      EMAIL_PORT: ${EMAIL_PORT:-587}
+      EMAIL_HOST_USER: ${EMAIL_HOST_USER:-}
+      EMAIL_HOST_PASSWORD: ${EMAIL_HOST_PASSWORD:-}
+      EMAIL_USE_TLS: ${EMAIL_USE_TLS:-True}
+      DEFAULT_FROM_EMAIL: ${DEFAULT_FROM_EMAIL:-noreply@localhost}
+      SITE_DOMAIN: ${SITE_DOMAIN:-localhost:8000}
+      VAPID_PUBLIC_KEY: ${VAPID_PUBLIC_KEY:-}
+      VAPID_PRIVATE_KEY: ${VAPID_PRIVATE_KEY:-}
+      VAPID_ADMIN_EMAIL: ${VAPID_ADMIN_EMAIL:-}
     networks:
       - backend
     depends_on:
@@ -120,13 +134,19 @@ services:
       redis:
         condition: service_healthy
     command: celery-worker
+    healthcheck:
+      test: ["CMD-SHELL", "ps aux | grep -v grep | grep 'celery.*worker' || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 30s
 
   # =================================================================
   # Celery Beat Service - Scheduled task scheduler
   # =================================================================
   celery-beat:
     build:
-      context: .
+      context: https://git.darksingularity.org/DarkSingularity/KeepItGoingServer.git#main
       dockerfile: Dockerfile
     container_name: keepitgoing-celery-beat
     restart: unless-stopped
@@ -135,6 +155,16 @@ services:
       SECRET_KEY: ${SECRET_KEY}
       DATABASE_URL: postgresql://${DB_USER:-keepitgoing}:${DB_PASSWORD}@postgres:5432/${DB_NAME:-keepitgoing}
       REDIS_URL: redis://redis:6379/0
+      EMAIL_HOST: ${EMAIL_HOST:-}
+      EMAIL_PORT: ${EMAIL_PORT:-587}
+      EMAIL_HOST_USER: ${EMAIL_HOST_USER:-}
+      EMAIL_HOST_PASSWORD: ${EMAIL_HOST_PASSWORD:-}
+      EMAIL_USE_TLS: ${EMAIL_USE_TLS:-True}
+      DEFAULT_FROM_EMAIL: ${DEFAULT_FROM_EMAIL:-noreply@localhost}
+      SITE_DOMAIN: ${SITE_DOMAIN:-localhost:8000}
+      VAPID_PUBLIC_KEY: ${VAPID_PUBLIC_KEY:-}
+      VAPID_PRIVATE_KEY: ${VAPID_PRIVATE_KEY:-}
+      VAPID_ADMIN_EMAIL: ${VAPID_ADMIN_EMAIL:-}
     networks:
       - backend
     depends_on:
@@ -143,6 +173,12 @@ services:
       redis:
         condition: service_healthy
     command: celery-beat
+    healthcheck:
+      test: ["CMD-SHELL", "ps aux | grep -v grep | grep 'celery.*beat' || exit 1"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
 
 # =================================================================
 # Named Volumes

notifications/admin.py

@@ -21,8 +21,8 @@ class NotificationAdmin(admin.ModelAdmin):
 class ScheduledReminderAdmin(admin.ModelAdmin):
     """Admin for ScheduledReminder."""
 
-    list_display = ['task', 'remind_at', 'is_sent', 'sent_at', 'created_at']
-    list_filter = ['is_sent', 'remind_at']
+    list_display = ['task', 'reminder_type', 'remind_at', 'is_sent', 'sent_at', 'created_at']
+    list_filter = ['reminder_type', 'is_sent', 'remind_at']
     search_fields = ['task__title']
     ordering = ['remind_at']
     raw_id_fields = ['task']

notifications/migrations/0004_scheduledreminder_reminder_type_and_more.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.2.9 on 2026-09-05 15:41
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('notifications', '0003_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='scheduledreminder',
+            name='reminder_type',
+            field=models.CharField(choices=[('reminder', 'Before Due'), ('due_soon', 'Due Now'), ('overdue', 'Overdue')], default='reminder', max_length=20),
+        ),
+        migrations.AlterField(
+            model_name='notification',
+            name='notification_type',
+            field=models.CharField(choices=[('reminder', 'Task Reminder'), ('due_soon', 'Due Soon'), ('overdue', 'Overdue'), ('shared', 'Task Shared'), ('comment', 'Comment'), ('daily_email', 'Daily Email')], max_length=20),
+        ),
+    ]

notifications/models.py

@@ -17,6 +17,7 @@ class Notification(models.Model):
         ('overdue', 'Overdue'),
         ('shared', 'Task Shared'),
         ('comment', 'Comment'),
+        ('daily_email', 'Daily Email'),
     ]
 
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
@@ -49,14 +50,23 @@ class Notification(models.Model):
 
 class ScheduledReminder(models.Model):
     """
-    Tracks scheduled reminders for tasks.
+    Tracks scheduled reminders for tasks. Rows are (re)created by
+    Task.reschedule_reminders() whenever a task's due info changes, and
+    consumed by notifications.tasks.send_scheduled_reminders().
     """
+    REMINDER_TYPES = [
+        ('reminder', 'Before Due'),
+        ('due_soon', 'Due Now'),
+        ('overdue', 'Overdue'),
+    ]
+
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     task = models.ForeignKey(
         'tasks.Task',
         on_delete=models.CASCADE,
         related_name='scheduled_reminders'
     )
+    reminder_type = models.CharField(max_length=20, choices=REMINDER_TYPES, default='reminder')
     remind_at = models.DateTimeField()
     is_sent = models.BooleanField(default=False)
     sent_at = models.DateTimeField(null=True, blank=True)
@@ -67,4 +77,4 @@ class ScheduledReminder(models.Model):
         ordering = ['remind_at']
 
     def __str__(self):
-        return f"Reminder for {self.task.title} at {self.remind_at}"
+        return f"{self.get_reminder_type_display()} for {self.task.title} at {self.remind_at}"

notifications/serializers.py

@@ -25,5 +25,5 @@ class ScheduledReminderSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = ScheduledReminder
-        fields = ['id', 'task', 'remind_at', 'is_sent', 'sent_at', 'created_at']
+        fields = ['id', 'task', 'reminder_type', 'remind_at', 'is_sent', 'sent_at', 'created_at']
         read_only_fields = ['id', 'is_sent', 'sent_at', 'created_at']

notifications/tasks.py

@@ -2,237 +2,302 @@
 Celery tasks for notifications.
 """
 
+import json
 import logging
 from celery import shared_task
 from django.utils import timezone
+from django.core.mail import send_mail
+from django.template.loader import render_to_string
+from django.conf import settings
+from django.db.models import Q
 from datetime import timedelta
+from zoneinfo import ZoneInfo
 
 logger = logging.getLogger(__name__)
 
 
-@shared_task
-def send_due_reminders():
+def notify_user(user, title, body, notification_type, task=None, url='/'):
     """
-    Check for tasks due soon and send reminders.
-    Runs every 5 minutes via Celery Beat.
+    Send a notification to a user via whichever of email/push they have
+    enabled, and record it in the Notification log. Returns True if it went
+    out on at least one channel.
     """
-    from tasks.models import Task
-    from users.models import DeviceToken
-    from .models import Notification, ScheduledReminder
-
-    now = timezone.now()
-
-    # Find scheduled reminders that need to be sent
-    reminders = ScheduledReminder.objects.filter(
-        remind_at__lte=now,
-        is_sent=False,
-        task__status__in=['pending', 'in_progress']
-    ).select_related('task', 'task__user')
-
-    for reminder in reminders:
-        task = reminder.task
-        user = task.user
-
-        # Create notification
-        Notification.objects.create(
-            user=user,
-            notification_type='reminder',
-            title=f'Reminder: {task.title}',
-            message=f'Task "{task.title}" is due soon.',
-            task=task,
-        )
-
-        # Send push notifications
-        send_push_to_user.delay(
-            user_id=str(user.id),
-            title=f'Reminder: {task.title}',
-            body=f'Task is due soon.',
-            data={'task_id': str(task.id)}
-        )
-
-        # Mark as sent
-        reminder.is_sent = True
-        reminder.sent_at = now
-        reminder.save()
-
-
-@shared_task
-def check_overdue_tasks():
-    """
-    Check for overdue tasks and notify users.
-    Runs daily.
-    """
-    from tasks.models import Task
     from .models import Notification
 
-    today = timezone.now().date()
+    notified = False
 
-    # Find overdue tasks that haven't been notified today
-    overdue_tasks = Task.objects.filter(
-        due_date__lt=today,
-        status__in=['pending', 'in_progress']
-    ).select_related('user')
+    if user.email_notifications and user.email_verified:
+        try:
+            send_mail(
+                subject=title,
+                message=body,
+                from_email=settings.DEFAULT_FROM_EMAIL,
+                recipient_list=[user.email],
+                fail_silently=False,
+            )
+            notified = True
+        except Exception as e:
+            logger.error(f"Failed to email {user.email}: {e}")
 
-    for task in overdue_tasks:
-        # Check if we already sent an overdue notification today
-        existing = Notification.objects.filter(
-            user=task.user,
+    if user.push_notifications:
+        send_web_push_to_user(user, title=title, body=body, url=url)
+        notified = True
+
+    if notified:
+        Notification.objects.create(
+            user=user,
+            notification_type=notification_type,
+            title=title,
+            message=body,
             task=task,
-            notification_type='overdue',
-            created_at__date=today
-        ).exists()
+        )
 
-        if not existing:
-            Notification.objects.create(
-                user=task.user,
-                notification_type='overdue',
-                title=f'Overdue: {task.title}',
-                message=f'Task "{task.title}" is overdue.',
-                task=task,
-            )
+    return notified
 
-            send_push_to_user.delay(
-                user_id=str(task.user.id),
-                title=f'Overdue: {task.title}',
-                body='This task is overdue.',
-                data={'task_id': str(task.id)}
+
+def send_web_push_to_user(user, title, body, url='/'):
+    """Send a Web Push notification to all of a user's registered web devices."""
+    if not settings.VAPID_PRIVATE_KEY:
+        return
+
+    from pywebpush import webpush, WebPushException
+    from users.models import DeviceToken
+
+    devices = DeviceToken.objects.filter(user=user, platform='web', is_active=True)
+
+    for device in devices:
+        try:
+            subscription_info = json.loads(device.token)
+        except (ValueError, TypeError):
+            continue
+
+        try:
+            webpush(
+                subscription_info=subscription_info,
+                data=json.dumps({'title': title, 'body': body, 'url': url}),
+                vapid_private_key=settings.VAPID_PRIVATE_KEY,
+                vapid_claims={'sub': f'mailto:{settings.VAPID_ADMIN_EMAIL}'},
             )
+        except WebPushException as e:
+            status_code = e.response.status_code if e.response is not None else None
+            if status_code in (404, 410):
+                device.is_active = False
+                device.save(update_fields=['is_active'])
+            logger.warning(f"Web push failed for {user.email}: {e}")
 
 
 @shared_task
-def send_push_to_user(user_id, title, body, data=None):
+def send_daily_task_email():
     """
-    Send push notification to all user devices.
+    Send daily email to users with their tasks due today.
+    Runs once per day and sends to users in their local morning time.
     """
     from django.contrib.auth import get_user_model
-    from users.models import DeviceToken
+    from tasks.models import Task
 
     User = get_user_model()
 
-    try:
-        user = User.objects.get(id=user_id)
-    except User.DoesNotExist:
-        return
+    # Get all users who have email and/or push notifications enabled
+    users = User.objects.filter(
+        Q(email_notifications=True) | Q(push_notifications=True),
+        is_active=True
+    ).distinct()
 
-    if not user.push_notifications:
-        return
+    notifications_sent = 0
+    current_utc_hour = timezone.now().hour
 
-    tokens = DeviceToken.objects.filter(user=user, is_active=True)
+    for user in users:
+        # Convert current UTC time to user's local time
+        try:
+            user_tz = ZoneInfo(user.timezone)
+        except Exception:
+            user_tz = ZoneInfo('UTC')
 
-    for token in tokens:
-        if token.platform == 'android':
-            send_fcm_notification.delay(token.token, title, body, data)
-        elif token.platform == 'web':
-            send_web_push_notification.delay(token.token, title, body, data)
-        elif token.platform == 'desktop':
-            # Desktop notifications are handled via WebSocket
-            pass
+        user_local_time = timezone.now().astimezone(user_tz)
+        user_local_hour = user_local_time.hour
+
+        # Only send if it's between 6-7 AM in the user's timezone
+        # (gives 1 hour window, task runs every hour)
+        if not (6 <= user_local_hour < 7):
+            continue
+
+        # Get today's date in user's timezone
+        today = user_local_time.date()
+
+        # Check if we already sent an email today
+        from .models import Notification
+        already_sent_today = Notification.objects.filter(
+            user=user,
+            notification_type='daily_email',
+            created_at__date=today
+        ).exists()
+
+        if already_sent_today:
+            continue
+
+        # Get tasks due today
+        tasks_due_today = Task.objects.filter(
+            user=user,
+            due_date=today,
+            status__in=['pending', 'in_progress']
+        ).order_by('due_time', 'priority', 'title')
+
+        # Get overdue tasks
+        overdue_tasks = Task.objects.filter(
+            user=user,
+            due_date__lt=today,
+            status__in=['pending', 'in_progress']
+        ).order_by('due_date', 'due_time', 'priority', 'title')
+
+        # Only send email if there are tasks
+        if not tasks_due_today.exists() and not overdue_tasks.exists():
+            continue
+
+        # Prepare email content
+        subject = f"Your tasks for {today.strftime('%A, %B %d, %Y')}"
+
+        # Create plain text message
+        message_lines = [
+            f"Good morning! Here are your tasks for today:\n"
+        ]
+
+        if overdue_tasks.exists():
+            message_lines.append(f"\n⚠️  OVERDUE TASKS ({overdue_tasks.count()}):")
+            for task in overdue_tasks[:10]:  # Limit to 10
+                due_str = task.due_date.strftime('%b %d')
+                message_lines.append(f"  • {task.title} (due {due_str})")
+            if overdue_tasks.count() > 10:
+                message_lines.append(f"  ... and {overdue_tasks.count() - 10} more")
+
+        if tasks_due_today.exists():
+            message_lines.append(f"\n📅 DUE TODAY ({tasks_due_today.count()}):")
+            for task in tasks_due_today:
+                time_str = task.due_time.strftime('%I:%M %p') if task.due_time else ''
+                priority_icon = {'high': '🔴', 'medium': '🟡', 'low': '🟢'}.get(task.priority, '')
+                message_lines.append(f"  • {priority_icon} {task.title} {time_str}".strip())
+
+        message_lines.append(f"\n\nView all tasks: https://{settings.SITE_DOMAIN}")
+        message_lines.append("\nYou can change your email preferences in your profile settings.")
+
+        message = '\n'.join(message_lines)
+
+        notified = False
+
+        # Send email
+        if user.email_notifications and user.email_verified:
+            try:
+                send_mail(
+                    subject=subject,
+                    message=message,
+                    from_email=settings.DEFAULT_FROM_EMAIL,
+                    recipient_list=[user.email],
+                    fail_silently=False,
+                )
+                notified = True
+                logger.info(f"Sent daily task email to {user.email}")
+            except Exception as e:
+                logger.error(f"Failed to send daily email to {user.email}: {e}")
+
+        # Send push
+        if user.push_notifications:
+            send_web_push_to_user(
+                user,
+                title=subject,
+                body=f"{tasks_due_today.count()} due today, {overdue_tasks.count()} overdue",
+                url='/',
+            )
+            notified = True
+
+        if notified:
+            # Record that we notified the user today (prevents duplicates)
+            Notification.objects.create(
+                user=user,
+                notification_type='daily_email',
+                title=subject,
+                message=f"Daily notification sent with {tasks_due_today.count()} tasks due today and {overdue_tasks.count()} overdue tasks"
+            )
+            notifications_sent += 1
+
+    logger.info(f"Daily task notification job completed. Notified {notifications_sent} users.")
+    return notifications_sent
+
+
+REMINDER_MESSAGES = {
+    'reminder': lambda task: (f'Upcoming: {task.title}', f'"{task.title}" is due soon.'),
+    'due_soon': lambda task: (f'Due now: {task.title}', f'"{task.title}" is due now.'),
+    'overdue': lambda task: (f'Overdue: {task.title}', f'"{task.title}" is overdue.'),
+}
 
 
 @shared_task
-def send_fcm_notification(token, title, body, data=None):
-    """Send FCM notification to Android device."""
-    from django.conf import settings
-
-    # Only send if FCM is configured
-    if not getattr(settings, 'FCM_CREDENTIALS_PATH', None):
-        return
-
-    try:
-        import firebase_admin
-        from firebase_admin import credentials, messaging
-
-        # Initialize Firebase if not already done
-        if not firebase_admin._apps:
-            cred = credentials.Certificate(settings.FCM_CREDENTIALS_PATH)
-            firebase_admin.initialize_app(cred)
-
-        message = messaging.Message(
-            notification=messaging.Notification(
-                title=title,
-                body=body,
-            ),
-            data=data or {},
-            token=token,
-        )
-
-        messaging.send(message)
-
-    except Exception as e:
-        # Log error but don't fail
-        logger.error(f"FCM notification failed: {e}")
-
-
-@shared_task
-def send_web_push_notification(subscription_info, title, body, data=None):
-    """Send Web Push notification."""
-    from django.conf import settings
-
-    vapid_private_key = getattr(settings, 'VAPID_PRIVATE_KEY', None)
-    vapid_email = getattr(settings, 'VAPID_ADMIN_EMAIL', None)
-
-    if not vapid_private_key or not vapid_email:
-        return
-
-    try:
-        from pywebpush import webpush, WebPushException
-        import json
-
-        webpush(
-            subscription_info=json.loads(subscription_info),
-            data=json.dumps({
-                'title': title,
-                'body': body,
-                'data': data or {}
-            }),
-            vapid_private_key=vapid_private_key,
-            vapid_claims={'sub': f'mailto:{vapid_email}'}
-        )
-
-    except Exception as e:
-        logger.error(f"Web push notification failed: {e}")
-
-
-@shared_task
-def schedule_task_reminder(task_id):
+def send_scheduled_reminders():
     """
-    Schedule a reminder for a task based on its due date and user preferences.
-    Called when a task is created or updated.
+    Send "before due", "due now", and "overdue" notifications from
+    ScheduledReminder rows created by Task.reschedule_reminders(). Runs
+    frequently (every few minutes) since these are time-sensitive, unlike
+    the once-a-day digest above.
     """
-    from tasks.models import Task
     from .models import ScheduledReminder
 
-    try:
-        task = Task.objects.get(id=task_id)
-    except Task.DoesNotExist:
-        return
+    due_reminders = ScheduledReminder.objects.filter(
+        is_sent=False, remind_at__lte=timezone.now()
+    ).select_related('task', 'task__user')
 
-    # Remove existing scheduled reminders for this task
-    ScheduledReminder.objects.filter(task=task, is_sent=False).delete()
+    sent_count = 0
+    for reminder in due_reminders:
+        task = reminder.task
+        if not task.is_deleted and task.status not in ('completed', 'cancelled'):
+            title, body = REMINDER_MESSAGES[reminder.reminder_type](task)
+            if notify_user(task.user, title, body, reminder.reminder_type, task=task, url=f'/tasks/{task.id}/'):
+                sent_count += 1
 
-    # Only schedule if task has a reminder time or due date
-    if task.reminder_at:
-        ScheduledReminder.objects.create(
-            task=task,
-            remind_at=task.reminder_at
-        )
-    elif task.due_date:
-        # Default reminder based on user preference
-        reminder_minutes = task.user.default_reminder_minutes
-        if task.due_time:
-            from datetime import datetime
-            due_datetime = datetime.combine(task.due_date, task.due_time)
-            due_datetime = timezone.make_aware(due_datetime)
-        else:
-            # Default to 9 AM on due date
-            due_datetime = timezone.make_aware(
-                timezone.datetime.combine(task.due_date, timezone.datetime.min.time())
-            ).replace(hour=9)
+        reminder.is_sent = True
+        reminder.sent_at = timezone.now()
+        reminder.save(update_fields=['is_sent', 'sent_at'])
 
-        remind_at = due_datetime - timedelta(minutes=reminder_minutes)
+    return sent_count
 
-        if remind_at > timezone.now():
-            ScheduledReminder.objects.create(
-                task=task,
-                remind_at=remind_at
-            )
+
+@shared_task
+def process_recurring_tasks():
+    """
+    Process completed recurring tasks and create next instances.
+    This runs daily as a safety net to catch any tasks that weren't
+    automatically handled when marked as completed.
+    """
+    from tasks.models import Task
+
+    # Find completed recurring tasks from the last 48 hours
+    yesterday = timezone.now() - timedelta(days=2)
+
+    completed_recurring_tasks = Task.objects.filter(
+        status='completed',
+        recurrence__in=['daily', 'weekly', 'biweekly', 'monthly', 'yearly', 'custom'],
+        completed_at__gte=yesterday
+    ).exclude(recurrence='none')
+
+    tasks_created = 0
+    for task in completed_recurring_tasks:
+        # Check if a next recurrence already exists
+        next_due_date = task.calculate_next_due_date()
+        if next_due_date:
+            # Check if we already created this recurrence
+            # Check for any task (pending OR completed) to avoid duplicates
+            existing = Task.objects.filter(
+                user=task.user,
+                title=task.title,
+                due_date=next_due_date,
+                recurrence=task.recurrence
+            ).exists()
+
+            if not existing:
+                # Create the next recurrence
+                new_task = task.create_next_recurrence()
+                if new_task:
+                    tasks_created += 1
+                    logger.info(f"Created recurring task: {new_task.title} (due: {new_task.due_date})")
+
+    if tasks_created > 0:
+        logger.info(f"Created {tasks_created} recurring task instances")
+
+    return tasks_created

notifications/tests.py

@@ -1,3 +1,285 @@
-from django.test import TestCase
+from datetime import date, datetime, time as dt_time, timedelta
+from unittest.mock import patch
 
-# Create your tests here.
+from django.contrib.auth import get_user_model
+from django.core import mail
+from django.test import TestCase
+from django.utils import timezone as django_timezone
+
+from notifications.models import ScheduledReminder
+from notifications.tasks import send_scheduled_reminders
+from tasks.models import Task
+
+User = get_user_model()
+
+
+class RescheduleRemindersTests(TestCase):
+    """Tests for Task.reschedule_reminders(), triggered from Task.save()."""
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='reminderuser',
+            email='reminderuser@example.com',
+            password='testpass123',
+            default_reminder_minutes=30,
+        )
+
+    def reminder_types(self, task):
+        return set(
+            ScheduledReminder.objects.filter(task=task, is_sent=False).values_list('reminder_type', flat=True)
+        )
+
+    def test_due_time_task_gets_all_three_reminders(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        self.assertEqual(self.reminder_types(task), {'reminder', 'due_soon', 'overdue'})
+
+        before_due = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+        due_soon = ScheduledReminder.objects.get(task=task, reminder_type='due_soon')
+        overdue = ScheduledReminder.objects.get(task=task, reminder_type='overdue')
+
+        expected_due = django_timezone.make_aware(datetime(2026, 1, 15, 17, 0, 0))
+        self.assertEqual(due_soon.remind_at, expected_due)
+        self.assertEqual(overdue.remind_at, expected_due + timedelta(hours=1))
+        self.assertEqual(before_due.remind_at, expected_due - timedelta(minutes=30))
+
+    def test_date_only_task_only_gets_overdue_reminder_next_day(self):
+        task = Task.objects.create(user=self.user, title='Task', due_date=date(2026, 1, 15))
+        self.assertEqual(self.reminder_types(task), {'overdue'})
+        overdue = ScheduledReminder.objects.get(task=task, reminder_type='overdue')
+        self.assertEqual(overdue.remind_at, django_timezone.make_aware(datetime(2026, 1, 16, 0, 0, 0)))
+
+    def test_no_reminder_minutes_skips_before_due_reminder(self):
+        self.user.default_reminder_minutes = 0
+        self.user.save()
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        self.assertEqual(self.reminder_types(task), {'due_soon', 'overdue'})
+
+    def test_explicit_reminder_at_overrides_default_minutes(self):
+        custom_reminder = django_timezone.make_aware(datetime(2026, 1, 15, 9, 0, 0))
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+            reminder_at=custom_reminder,
+        )
+        before_due = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+        self.assertEqual(before_due.remind_at, custom_reminder)
+
+    def test_no_due_date_gets_no_reminders(self):
+        task = Task.objects.create(user=self.user, title='Task')
+        self.assertEqual(self.reminder_types(task), set())
+
+    def test_completing_task_clears_pending_reminders(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        self.assertTrue(ScheduledReminder.objects.filter(task=task, is_sent=False).exists())
+        task.status = 'completed'
+        task.save()
+        self.assertFalse(ScheduledReminder.objects.filter(task=task, is_sent=False).exists())
+
+    def test_deleting_task_clears_pending_reminders(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        task.is_deleted = True
+        task.save()
+        self.assertFalse(ScheduledReminder.objects.filter(task=task, is_sent=False).exists())
+
+    def test_changing_due_date_replaces_reminders(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        task.due_date = date(2026, 2, 1)
+        task.save()
+        self.assertEqual(ScheduledReminder.objects.filter(task=task, is_sent=False).count(), 3)
+        due_soon = ScheduledReminder.objects.get(task=task, reminder_type='due_soon')
+        self.assertEqual(due_soon.remind_at, django_timezone.make_aware(datetime(2026, 2, 1, 17, 0, 0)))
+
+    def test_unrelated_field_save_does_not_duplicate_reminders(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        task.title = 'Renamed task'
+        task.save()
+        self.assertEqual(ScheduledReminder.objects.filter(task=task, is_sent=False).count(), 3)
+
+
+class DefaultReminderMinutesChangeTests(TestCase):
+    """
+    Task.reschedule_reminders() only captures user.default_reminder_minutes
+    at the moment a task's own due_date/due_time is set - changing the
+    profile setting afterward doesn't reach existing tasks on its own.
+    User.reschedule_reminder_notifications(), triggered from User.save()
+    when the setting changes, is what makes that retroactive.
+    """
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='reminderuser2', email='reminderuser2@example.com', password='testpass123',
+            default_reminder_minutes=30,
+        )
+
+    def test_changing_default_minutes_reschedules_before_due_reminder(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        due_moment = django_timezone.make_aware(datetime(2026, 1, 15, 17, 0, 0))
+        before_due = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+        self.assertEqual(before_due.remind_at, due_moment - timedelta(minutes=30))
+
+        self.user.default_reminder_minutes = 15
+        self.user.save()
+
+        before_due = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+        self.assertEqual(before_due.remind_at, due_moment - timedelta(minutes=15))
+
+    def test_task_with_explicit_reminder_at_is_left_alone(self):
+        custom_reminder = django_timezone.make_aware(datetime(2026, 1, 15, 9, 0, 0))
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+            reminder_at=custom_reminder,
+        )
+
+        self.user.default_reminder_minutes = 15
+        self.user.save()
+
+        before_due = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+        self.assertEqual(before_due.remind_at, custom_reminder)
+
+    def test_completed_task_is_not_touched(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0), status='completed',
+        )
+        self.assertFalse(ScheduledReminder.objects.filter(task=task, is_sent=False).exists())
+
+        self.user.default_reminder_minutes = 15
+        self.user.save()
+
+        self.assertFalse(ScheduledReminder.objects.filter(task=task, is_sent=False).exists())
+
+    def test_unrelated_profile_field_save_does_not_reschedule(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        original_id = ScheduledReminder.objects.get(task=task, reminder_type='reminder').id
+
+        self.user.first_name = 'Changed'
+        self.user.save()
+
+        # Same row (not deleted and recreated by reschedule_reminders()).
+        self.assertEqual(ScheduledReminder.objects.get(task=task, reminder_type='reminder').id, original_id)
+
+
+class SendScheduledRemindersTests(TestCase):
+    """Tests for the send_scheduled_reminders Celery task."""
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='sendreminderuser',
+            email='sendreminderuser@example.com',
+            password='testpass123',
+            email_notifications=True,
+            push_notifications=False,
+            email_verified=True,
+            default_reminder_minutes=30,
+        )
+
+    def test_due_reminder_sends_email_and_marks_sent(self):
+        task = Task.objects.create(
+            user=self.user, title='Water the plants', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        reminder = ScheduledReminder.objects.get(task=task, reminder_type='due_soon')
+
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = reminder.remind_at + timedelta(seconds=1)
+            sent_count = send_scheduled_reminders()
+
+        # "reminder" (30 min before) and "due_soon" have passed; "overdue"
+        # is delayed an hour past due_soon so it hasn't fired yet.
+        self.assertEqual(sent_count, 2)
+        self.assertEqual(len(mail.outbox), 2)
+        reminder.refresh_from_db()
+        self.assertTrue(reminder.is_sent)
+        self.assertIsNotNone(reminder.sent_at)
+        self.assertFalse(ScheduledReminder.objects.get(task=task, reminder_type='overdue').is_sent)
+
+    def test_overdue_reminder_fires_an_hour_after_due(self):
+        task = Task.objects.create(
+            user=self.user, title='Water the plants', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        overdue = ScheduledReminder.objects.get(task=task, reminder_type='overdue')
+        due_soon = ScheduledReminder.objects.get(task=task, reminder_type='due_soon')
+        self.assertEqual(overdue.remind_at, due_soon.remind_at + timedelta(hours=1))
+
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = overdue.remind_at + timedelta(seconds=1)
+            send_scheduled_reminders()
+
+        overdue.refresh_from_db()
+        self.assertTrue(overdue.is_sent)
+        self.assertIn(f'Overdue: {task.title}', [m.subject for m in mail.outbox])
+
+    def test_future_reminder_not_sent_yet(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 15, 8, 0, 0))
+            sent_count = send_scheduled_reminders()
+
+        self.assertEqual(sent_count, 0)
+        self.assertEqual(len(mail.outbox), 0)
+
+    def test_completed_task_reminder_marked_sent_without_notifying(self):
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        remind_at = ScheduledReminder.objects.get(task=task, reminder_type='due_soon').remind_at
+        task.status = 'completed'
+        task.save()  # reschedule_reminders() already clears pending reminders for the task
+
+        # Simulate a stale reminder surviving anyway (e.g. a race with the poller).
+        stale = ScheduledReminder.objects.create(task=task, reminder_type='due_soon', remind_at=remind_at)
+
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = remind_at + timedelta(seconds=1)
+            send_scheduled_reminders()
+
+        self.assertEqual(len(mail.outbox), 0)
+        stale.refresh_from_db()
+        self.assertTrue(stale.is_sent)
+
+    def test_channel_choice_email_only(self):
+        self.user.push_notifications = False
+        self.user.save()
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        reminder = ScheduledReminder.objects.get(task=task, reminder_type='reminder')
+
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = reminder.remind_at + timedelta(seconds=1)
+            send_scheduled_reminders()
+
+        sent_subjects = [m.subject for m in mail.outbox]
+        self.assertIn(f'Upcoming: {task.title}', sent_subjects)
+
+    def test_channel_choice_none_still_marks_sent(self):
+        self.user.email_notifications = False
+        self.user.push_notifications = False
+        self.user.save()
+        task = Task.objects.create(
+            user=self.user, title='Task', due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0),
+        )
+        reminder = ScheduledReminder.objects.get(task=task, reminder_type='due_soon')
+
+        with patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = reminder.remind_at + timedelta(seconds=1)
+            send_scheduled_reminders()
+
+        self.assertEqual(len(mail.outbox), 0)
+        reminder.refresh_from_db()
+        self.assertTrue(reminder.is_sent)

stack.env.example

@@ -0,0 +1,142 @@
+# ===================================================================
+# KeepItGoing Server - Portainer Stack Environment Configuration
+# ===================================================================
+# This file is an EXAMPLE for Portainer deployments from git repository.
+# When deploying in Portainer:
+# 1. Copy the contents of this file
+# 2. Paste into the "Environment variables" section in Portainer
+# 3. Replace all placeholder values with your actual values
+# DO NOT commit your actual stack.env file to version control!
+
+# ===================================================================
+# Django Core Settings
+# ===================================================================
+
+# SECURITY WARNING: Generate a strong secret key!
+# Generate with: python -c "from django.core.management.utils import get_random_secret_key; print(get_random_secret_key())"
+SECRET_KEY=CHANGE_ME_GENERATE_A_STRONG_SECRET_KEY_50_PLUS_CHARACTERS
+
+# Debug mode (MUST be False in production)
+DEBUG=False
+
+# Comma-separated list of allowed hosts
+# Example: api.yourdomain.com,localhost
+ALLOWED_HOSTS=yourdomain.com,localhost
+
+# Comma-separated list of trusted origins for CSRF (must include https://)
+# Example: https://api.yourdomain.com,https://yourdomain.com
+CSRF_TRUSTED_ORIGINS=https://yourdomain.com
+
+# Domain used in email links
+SITE_DOMAIN=yourdomain.com
+
+# Public self-registration toggle
+# Set to False to require admin-created accounts
+ALLOW_SELF_REGISTRATION=False
+
+# ===================================================================
+# Database Configuration (PostgreSQL)
+# ===================================================================
+
+DB_NAME=keepitgoing
+DB_USER=keepitgoing
+DB_PASSWORD=CHANGE_ME_STRONG_DATABASE_PASSWORD
+
+# ===================================================================
+# Redis Configuration
+# ===================================================================
+
+REDIS_URL=redis://redis:6379/0
+
+# ===================================================================
+# Email Configuration
+# ===================================================================
+# Required for email verification, approval emails, and notifications
+
+EMAIL_BACKEND=django.core.mail.backends.smtp.EmailBackend
+
+# Gmail Example (use App Password, not regular password):
+# EMAIL_HOST=smtp.gmail.com
+# EMAIL_PORT=587
+# EMAIL_USE_TLS=True
+# EMAIL_HOST_USER=your-email@gmail.com
+# EMAIL_HOST_PASSWORD=your-app-password
+
+# SendGrid Example:
+# EMAIL_HOST=smtp.sendgrid.net
+# EMAIL_PORT=587
+# EMAIL_USE_TLS=True
+# EMAIL_HOST_USER=apikey
+# EMAIL_HOST_PASSWORD=your-sendgrid-api-key
+
+# AWS SES Example:
+# EMAIL_HOST=email-smtp.us-east-1.amazonaws.com
+# EMAIL_PORT=587
+# EMAIL_USE_TLS=True
+# EMAIL_HOST_USER=your-aws-access-key
+# EMAIL_HOST_PASSWORD=your-aws-secret-key
+
+EMAIL_HOST=smtp.gmail.com
+EMAIL_PORT=587
+EMAIL_USE_TLS=True
+EMAIL_HOST_USER=your-email@gmail.com
+EMAIL_HOST_PASSWORD=your-app-password
+DEFAULT_FROM_EMAIL=KeepItGoing <noreply@yourdomain.com>
+SERVER_EMAIL=server@yourdomain.com
+
+# ===================================================================
+# Email Verification Settings
+# ===================================================================
+
+EMAIL_VERIFICATION_TOKEN_EXPIRY_HOURS=24
+
+# ===================================================================
+# CORS Configuration
+# ===================================================================
+# Comma-separated list of allowed origins
+# Example: https://yourdomain.com,https://app.yourdomain.com
+
+CORS_ALLOWED_ORIGINS=https://yourdomain.com
+
+# ===================================================================
+# SaaS Mode
+# ===================================================================
+# Set to True for SaaS deployment with billing/usage limits
+# Set to False for self-hosted deployment (no limits)
+
+SAAS_MODE=False
+
+# ===================================================================
+# Web Server Configuration
+# ===================================================================
+
+# Port to expose the web service on (default: 8000)
+# Change this if port 8000 is already in use
+WEB_PORT=8000
+
+# ===================================================================
+# Gunicorn Configuration
+# ===================================================================
+
+GUNICORN_WORKERS=3
+GUNICORN_TIMEOUT=60
+
+# ===================================================================
+# Push Notifications (Optional)
+# ===================================================================
+# Leave empty if not using push notifications
+
+# Firebase Cloud Messaging (FCM)
+FCM_CREDENTIALS_PATH=
+
+# Web Push (VAPID keys)
+VAPID_PUBLIC_KEY=
+VAPID_PRIVATE_KEY=
+VAPID_ADMIN_EMAIL=
+
+# ===================================================================
+# Additional Settings
+# ===================================================================
+
+# Django settings module (usually don't need to change)
+DJANGO_SETTINGS_MODULE=config.settings.selfhosted

static/css/app.css

@@ -91,6 +91,36 @@
     --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.3);
 }
 
+/* ============================================
+   Scrollbar Styling
+   ============================================ */
+
+/* Firefox scrollbar styling */
+* {
+    scrollbar-width: thin;
+    scrollbar-color: var(--border) var(--surface);
+}
+
+/* Chromium/Webkit scrollbar styling */
+*::-webkit-scrollbar {
+    width: 12px;
+    height: 12px;
+}
+
+*::-webkit-scrollbar-track {
+    background: var(--surface);
+}
+
+*::-webkit-scrollbar-thumb {
+    background-color: var(--border);
+    border-radius: 6px;
+    border: 3px solid var(--surface);
+}
+
+*::-webkit-scrollbar-thumb:hover {
+    background-color: var(--surface-hover);
+}
+
 /* ============================================
    Reset & Base
    ============================================ */
@@ -857,6 +887,34 @@ a:hover {
     font-size: var(--font-sm);
 }
 
+/* Sidebar toggle button (hidden on desktop, shown on mobile) */
+.sidebar-toggle {
+    display: none;
+    background: none;
+    border: none;
+    padding: var(--space-sm);
+    cursor: pointer;
+    color: var(--text-secondary);
+}
+
+.sidebar-toggle svg {
+    width: 24px;
+    height: 24px;
+}
+
+/* Mobile overlay - removed dark background, sidebar slides over content */
+.mobile-overlay {
+    display: none;
+    position: fixed;
+    inset: 0;
+    background-color: transparent;
+    z-index: 40;
+}
+
+.mobile-overlay.visible {
+    display: block;
+}
+
 /* ============================================
    Mobile Responsive
    ============================================ */
@@ -886,19 +944,53 @@ a:hover {
         --sidebar-width: 0;
     }
 
-    .app-layout {
+    /* Override both app-layout variants to use single column */
+    .app-layout,
+    .app-layout.detail-closed {
         grid-template-columns: 1fr;
     }
 
+    /* Explicit grid positioning for mobile */
+    .app-header {
+        grid-row: 1;
+        grid-column: 1;
+        padding: var(--space-sm) var(--space-md);
+    }
+
+    /* Force task pane into the single column with full width */
+    .task-pane {
+        grid-row: 2;
+        grid-column: 1;
+        width: 100%;
+        min-width: 0;
+        max-width: 100%;
+    }
+
+    .header-user span {
+        display: none; /* Hide email on mobile */
+    }
+
+    .app-header-actions {
+        gap: var(--space-xs);
+    }
+
+    .app-brand {
+        font-size: 1.1rem; /* Slightly smaller on mobile */
+    }
+
+    /* Sidebar drawer - improved positioning */
     .app-sidebar {
         position: fixed;
         left: 0;
         top: var(--header-height);
         bottom: 0;
-        width: 260px;
-        z-index: 50;
+        width: 280px; /* Slightly wider for touch targets */
+        z-index: 100; /* Higher z-index */
         transform: translateX(-100%);
-        transition: transform var(--anim-normal);
+        transition: transform 0.3s ease-in-out;
+        background-color: var(--surface);
+        box-shadow: var(--shadow-lg);
+        overflow-y: auto;
     }
 
     .app-sidebar.open {
@@ -909,40 +1001,128 @@ a:hover {
         display: flex;
     }
 
+    /* Detail pane mobile */
     .detail-pane {
         width: 100%;
+        max-width: 100vw;
+        padding: var(--space-md);
     }
 
+    /* Forms */
     .form-row {
         grid-template-columns: 1fr;
     }
+
+    .form-group {
+        margin-bottom: var(--space-md);
+    }
+
+    /* Task list mobile optimization */
+    .task-item {
+        padding: var(--space-sm);
+    }
+
+    .task-meta {
+        flex-wrap: wrap;
+        gap: var(--space-xs);
+        font-size: 0.75rem;
+    }
+
+    .priority-badge {
+        font-size: 0.7rem;
+        padding: 2px 6px;
+    }
+
+    .tag {
+        font-size: 0.7rem;
+        padding: 2px 6px;
+        max-width: 100px;
+        overflow: hidden;
+        text-overflow: ellipsis;
+    }
+
+    /* Touch targets - 44px minimum */
+    .task-item-checkbox {
+        width: 24px;
+        height: 24px;
+    }
+
+    .btn {
+        min-height: 44px;
+        padding: var(--space-sm) var(--space-md);
+    }
+
+    .sidebar-toggle {
+        min-width: 44px;
+        min-height: 44px;
+        padding: var(--space-sm);
+    }
+
+    .theme-toggle {
+        min-width: 44px;
+        min-height: 44px;
+    }
+
+    /* Modal on mobile */
+    .modal {
+        width: 95%;
+        max-width: 400px;
+        max-height: 90vh;
+        overflow-y: auto;
+    }
+
+    /* Mobile utility classes */
+    .mobile-only {
+        display: block;
+    }
+
+    .desktop-only {
+        display: none !important;
+    }
+
+    .mobile-full-width {
+        width: 100% !important;
+    }
 }
 
-/* Sidebar toggle button (visible on mobile) */
-.sidebar-toggle {
+/* Very small phones breakpoint */
+@media (max-width: 480px) {
+    .app-header {
+        padding: var(--space-xs) var(--space-sm);
+    }
+
+    .app-brand {
+        font-size: 0.9rem;
+    }
+
+    .app-sidebar {
+        width: 260px; /* Narrower on very small screens */
+    }
+
+    /* Smaller buttons on very small screens */
+    .header-user .btn {
+        font-size: 0.75rem;
+        padding: var(--space-xs) var(--space-sm);
+        min-height: 36px;
+    }
+
+    .theme-toggle {
+        min-width: 40px;
+        min-height: 40px;
+    }
+
+    .sidebar-toggle {
+        min-width: 40px;
+        min-height: 40px;
+    }
+}
+
+/* Mobile utility classes base definitions */
+.mobile-only {
     display: none;
-    background: none;
-    border: none;
-    padding: var(--space-sm);
-    cursor: pointer;
-    color: var(--text-secondary);
 }
 
-.sidebar-toggle svg {
-    width: 24px;
-    height: 24px;
-}
-
-/* Mobile overlay */
-.mobile-overlay {
-    display: none;
-    position: fixed;
-    inset: 0;
-    background-color: rgba(0, 0, 0, 0.5);
-    z-index: 40;
-}
-
-.mobile-overlay.visible {
+.desktop-only {
     display: block;
 }
 

static/js/app.js

@@ -3,12 +3,123 @@
  * Handles theme toggle, task selection, mobile menus, and AJAX operations
  */
 
-document.addEventListener('DOMContentLoaded', function() {
+document.addEventListener('DOMContentLoaded', async function() {
     initTheme();
     initTaskSelection();
     initTimerDisplays();
+    registerServiceWorker();
+    // Every real page load is a chance for the online UI to have mutated
+    // something (a tag delete, a task edit) that IndexedDB doesn't know
+    // about yet - sync unconditionally (no throttle) so the offline cache
+    // never lags behind what the user just did while online. The server's
+    // own rate limit (SyncRateThrottle) is the backstop against excess calls.
+    const pushedChanges = await runBackgroundSync();
+    if (pushedChanges) {
+        window.location.reload();
+    }
 });
 
+window.addEventListener('online', async function() {
+    const pushedChanges = await runBackgroundSync();
+    if (pushedChanges) {
+        window.location.reload();
+    }
+});
+
+/* ============================================
+   Service Worker
+   ============================================ */
+
+function registerServiceWorker() {
+    if ('serviceWorker' in navigator) {
+        navigator.serviceWorker.register('/sw.js');
+    }
+}
+
+/* ============================================
+   Push Notifications
+   ============================================ */
+
+function urlBase64ToUint8Array(base64String) {
+    const padding = '='.repeat((4 - (base64String.length % 4)) % 4);
+    const base64 = (base64String + padding).replace(/-/g, '+').replace(/_/g, '/');
+    const rawData = window.atob(base64);
+    const outputArray = new Uint8Array(rawData.length);
+    for (let i = 0; i < rawData.length; i++) {
+        outputArray[i] = rawData.charCodeAt(i);
+    }
+    return outputArray;
+}
+
+async function subscribeToPush(vapidPublicKey) {
+    if (!('serviceWorker' in navigator) || !('PushManager' in window)) {
+        throw new Error('Push notifications are not supported in this browser.');
+    }
+    if (!vapidPublicKey) {
+        throw new Error('Push notifications are not configured on this server.');
+    }
+
+    const permission = await Notification.requestPermission();
+    if (permission !== 'granted') {
+        throw new Error('Notification permission was not granted.');
+    }
+
+    const registration = await navigator.serviceWorker.ready;
+    let subscription = await registration.pushManager.getSubscription();
+    if (!subscription) {
+        subscription = await registration.pushManager.subscribe({
+            userVisibleOnly: true,
+            applicationServerKey: urlBase64ToUint8Array(vapidPublicKey),
+        });
+    }
+
+    const csrfToken = document.querySelector('[name=csrfmiddlewaretoken]').value;
+    const response = await fetch('/api/users/devices/', {
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/json',
+            'X-CSRFToken': csrfToken,
+        },
+        body: JSON.stringify({
+            platform: 'web',
+            token: JSON.stringify(subscription),
+            device_name: navigator.userAgent.slice(0, 255),
+        }),
+    });
+
+    if (!response.ok) {
+        throw new Error('Failed to register push subscription with the server.');
+    }
+}
+
+function handleProfileFormSubmit(event, form) {
+    const pushCheckbox = form.querySelector('[name=push_notifications]');
+    if (!pushCheckbox || !pushCheckbox.checked) {
+        return;
+    }
+
+    // preventDefault() must happen synchronously (before any await) or the
+    // browser will have already submitted the form by the time we get to it.
+    event.preventDefault();
+    enablePushThenSubmitProfile(form, pushCheckbox);
+}
+
+async function enablePushThenSubmitProfile(form, pushCheckbox) {
+    try {
+        if ('serviceWorker' in navigator && 'PushManager' in window) {
+            const registration = await navigator.serviceWorker.getRegistration();
+            const existing = registration && await registration.pushManager.getSubscription();
+            if (!existing) {
+                await subscribeToPush(pushCheckbox.dataset.vapidPublicKey);
+            }
+        }
+    } catch (err) {
+        alert('Could not enable push notifications: ' + err.message);
+        pushCheckbox.checked = false;
+    }
+    form.submit();
+}
+
 /* ============================================
    Theme Toggle
    ============================================ */
@@ -162,6 +273,74 @@ function closeDetail() {
     closeMobileMenus();
 }
 
+/* ============================================
+   Custom Recurrence Builder
+   ============================================ */
+
+function toggleCustomRecurrenceBuilder(selectEl) {
+    const form = selectEl.closest('form');
+    const builder = form.querySelector('.custom-recurrence-builder');
+    if (builder) {
+        builder.classList.toggle('hidden', selectEl.value !== 'custom');
+    }
+}
+
+function toggleCustomFreqPanel(radioEl) {
+    const builder = radioEl.closest('.custom-recurrence-builder');
+    const weeklyPanel = builder.querySelector('.custom-weekly-panel');
+    const monthlyPanel = builder.querySelector('.custom-monthly-panel');
+    weeklyPanel.classList.toggle('hidden', radioEl.value !== 'weekly');
+    monthlyPanel.classList.toggle('hidden', radioEl.value !== 'monthly');
+}
+
+function assembleCustomRecurrenceRule(formEl) {
+    const recurrenceSelect = formEl.querySelector('[name="recurrence"]');
+    const ruleInput = formEl.querySelector('[name="recurrence_rule"]');
+    if (!recurrenceSelect || !ruleInput) {
+        return true;
+    }
+
+    if (recurrenceSelect.value !== 'custom') {
+        ruleInput.value = '';
+        return true;
+    }
+
+    const builder = formEl.querySelector('.custom-recurrence-builder');
+    if (!builder) {
+        return true;
+    }
+
+    const freqMode = builder.querySelector('.custom-freq-mode:checked');
+    const freq = freqMode ? freqMode.value : 'weekly';
+
+    if (freq === 'weekly') {
+        const panel = builder.querySelector('.custom-weekly-panel');
+        const interval = parseInt(panel.querySelector('.custom-interval').value, 10) || 1;
+        const days = Array.from(panel.querySelectorAll('.custom-weekday:checked')).map(cb => cb.value);
+        if (days.length === 0) {
+            ruleInput.value = '';
+            return true;
+        }
+        ruleInput.value = `FREQ=WEEKLY;INTERVAL=${interval};BYDAY=${days.join(',')}`;
+    } else {
+        const panel = builder.querySelector('.custom-monthly-panel');
+        const interval = parseInt(panel.querySelector('.custom-interval').value, 10) || 1;
+        const monthlyMode = panel.querySelector('.custom-monthly-mode:checked');
+        const mode = monthlyMode ? monthlyMode.value : 'day';
+
+        if (mode === 'day') {
+            const day = parseInt(panel.querySelector('.custom-bymonthday').value, 10) || 1;
+            ruleInput.value = `FREQ=MONTHLY;INTERVAL=${interval};BYMONTHDAY=${day}`;
+        } else {
+            const ordinal = panel.querySelector('.custom-nth-ordinal').value;
+            const weekday = panel.querySelector('.custom-nth-weekday').value;
+            ruleInput.value = `FREQ=MONTHLY;INTERVAL=${interval};BYDAY=${ordinal}${weekday}`;
+        }
+    }
+
+    return true;
+}
+
 /* ============================================
    Mobile Navigation
    ============================================ */

static/js/offline-db.js

@@ -0,0 +1,118 @@
+/**
+ * KeepItGoing - Offline IndexedDB helpers
+ * Pure local storage access for offline task data. No network calls here —
+ * see offline-sync.js for the /api/sync/ replay logic.
+ */
+
+const OFFLINE_DB_NAME = 'keepitgoing-offline';
+const OFFLINE_DB_VERSION = 2;
+
+function openOfflineDB() {
+    return new Promise((resolve, reject) => {
+        const request = indexedDB.open(OFFLINE_DB_NAME, OFFLINE_DB_VERSION);
+
+        request.onupgradeneeded = (event) => {
+            const db = event.target.result;
+            if (!db.objectStoreNames.contains('tasks')) {
+                db.createObjectStore('tasks', { keyPath: 'sync_id' });
+            }
+            if (!db.objectStoreNames.contains('meta')) {
+                db.createObjectStore('meta', { keyPath: 'key' });
+            }
+            if (!db.objectStoreNames.contains('tags')) {
+                db.createObjectStore('tags', { keyPath: 'sync_id' });
+            }
+            if (!db.objectStoreNames.contains('time_entries')) {
+                db.createObjectStore('time_entries', { keyPath: 'sync_id' });
+            }
+        };
+
+        request.onsuccess = () => resolve(request.result);
+        request.onerror = () => reject(request.error);
+    });
+}
+
+function promisifyRequest(request) {
+    return new Promise((resolve, reject) => {
+        request.onsuccess = () => resolve(request.result);
+        request.onerror = () => reject(request.error);
+    });
+}
+
+async function getMeta(key) {
+    const db = await openOfflineDB();
+    const tx = db.transaction('meta', 'readonly');
+    const result = await promisifyRequest(tx.objectStore('meta').get(key));
+    return result ? result.value : undefined;
+}
+
+async function setMeta(key, value) {
+    const db = await openOfflineDB();
+    const tx = db.transaction('meta', 'readwrite');
+    await promisifyRequest(tx.objectStore('meta').put({ key, value }));
+}
+
+async function ensureDeviceId() {
+    let deviceId = await getMeta('device_id');
+    if (!deviceId) {
+        deviceId = 'web-' + crypto.randomUUID();
+        await setMeta('device_id', deviceId);
+    }
+    return deviceId;
+}
+
+async function getAllTasks() {
+    const db = await openOfflineDB();
+    const tx = db.transaction('tasks', 'readonly');
+    return promisifyRequest(tx.objectStore('tasks').getAll());
+}
+
+async function putLocalTask(task) {
+    const db = await openOfflineDB();
+    const tx = db.transaction('tasks', 'readwrite');
+    await promisifyRequest(tx.objectStore('tasks').put(task));
+}
+
+async function getDirtyTasks() {
+    const tasks = await getAllTasks();
+    return tasks.filter((t) => t._dirty === true);
+}
+
+async function getAllTags() {
+    const db = await openOfflineDB();
+    const tx = db.transaction('tags', 'readonly');
+    return promisifyRequest(tx.objectStore('tags').getAll());
+}
+
+async function putLocalTag(tag) {
+    const db = await openOfflineDB();
+    const tx = db.transaction('tags', 'readwrite');
+    await promisifyRequest(tx.objectStore('tags').put(tag));
+}
+
+async function getDirtyTags() {
+    const tags = await getAllTags();
+    return tags.filter((t) => t._dirty === true);
+}
+
+async function getAllTimeEntries() {
+    const db = await openOfflineDB();
+    const tx = db.transaction('time_entries', 'readonly');
+    return promisifyRequest(tx.objectStore('time_entries').getAll());
+}
+
+async function putLocalTimeEntry(entry) {
+    const db = await openOfflineDB();
+    const tx = db.transaction('time_entries', 'readwrite');
+    await promisifyRequest(tx.objectStore('time_entries').put(entry));
+}
+
+async function getDirtyTimeEntries() {
+    const entries = await getAllTimeEntries();
+    return entries.filter((e) => e._dirty === true);
+}
+
+async function getRunningTimeEntry() {
+    const entries = await getAllTimeEntries();
+    return entries.find((e) => !e.is_deleted && !e.ended_at) || null;
+}

static/js/offline-sync.js

@@ -0,0 +1,173 @@
+/**
+ * KeepItGoing - Offline sync replay
+ * Talks to /api/sync/ to pull server changes into IndexedDB and push any
+ * locally-queued offline edits back up. Only ever runs from a real,
+ * network-loaded page (never from the cached offline app).
+ */
+
+// Bump this whenever a previously-untracked entity type starts being synced
+// (e.g. tags/time_entries were added after tasks-only syncing already
+// shipped). /api/sync/ only returns rows changed since a device's last sync
+// token, so any device with an old token would otherwise never receive
+// pre-existing rows of the newly-tracked type - they were never "changed
+// since" a token issued before that type existed at all. Forces exactly one
+// full resync (by clearing the stored token) per bump, per device.
+const SYNC_FORMAT_VERSION = 2;
+
+function getCsrfToken() {
+    const el = document.querySelector('[name=csrfmiddlewaretoken]');
+    return el ? el.value : null;
+}
+
+function stripLocalFields(record) {
+    const { _dirty, _pending_conflict_id, ...clean } = record;
+    return clean;
+}
+
+// server_changes.time_entries[] uses a field named "task" holding the task's
+// sync_id, but *creating* a new entry requires "task_sync_id" instead
+// (sync/views.py process_time_entry_changes). Normalize to task_sync_id
+// locally so the rest of the app only ever deals with one field name.
+function timeEntryToWire(entry) {
+    return stripLocalFields(entry);
+}
+
+function timeEntryFromWire(serverEntry) {
+    const { task, ...rest } = serverEntry;
+    // duration_seconds isn't part of the sync wire format at all (a
+    // pre-existing gap in TimeEntrySyncSerializer) - compute it locally so
+    // the offline app's time totals are correct regardless of where an
+    // entry came from.
+    const durationSeconds = rest.ended_at
+        ? Math.round((new Date(rest.ended_at) - new Date(rest.started_at)) / 1000)
+        : null;
+    return { ...rest, task_sync_id: task, duration_seconds: durationSeconds };
+}
+
+// Shared merge-then-auto-resolve logic for one entity type's slice of a
+// sync response: merge server rows (skipping anything about to be
+// re-asserted by a conflict resolution), clear dirty flags for rows that
+// synced cleanly, then resolve each conflict as "local wins".
+async function mergeAndResolveEntity({ entityType, dirtyLocal, serverRows, conflicts, csrfToken, putLocal, fromWire }) {
+    const normalize = fromWire || ((r) => r);
+    const relevantConflicts = conflicts.filter((c) => c.entity_type === entityType);
+    const conflictedIds = new Set(
+        relevantConflicts.map((c) => c.local_data && c.local_data.sync_id).filter(Boolean)
+    );
+
+    for (const serverRow of serverRows) {
+        const normalized = normalize(serverRow);
+        if (conflictedIds.has(normalized.sync_id)) {
+            continue;
+        }
+        await putLocal({ ...normalized, _dirty: false, _pending_conflict_id: null });
+    }
+
+    for (const row of dirtyLocal) {
+        if (!conflictedIds.has(row.sync_id)) {
+            await putLocal({ ...row, _dirty: false, _pending_conflict_id: null });
+        }
+    }
+
+    for (const conflict of relevantConflicts) {
+        const syncId = conflict.local_data && conflict.local_data.sync_id;
+        if (!syncId) {
+            continue;
+        }
+        try {
+            const resolveResponse = await fetch(`/api/sync/conflicts/${conflict.id}/resolve/`, {
+                method: 'POST',
+                headers: {
+                    'Content-Type': 'application/json',
+                    'X-CSRFToken': csrfToken,
+                },
+                body: JSON.stringify({ resolution: 'local' }),
+            });
+            if (!resolveResponse.ok) {
+                throw new Error('resolve failed');
+            }
+            const localRow = dirtyLocal.find((r) => r.sync_id === syncId);
+            if (localRow) {
+                await putLocal({ ...localRow, _dirty: false, _pending_conflict_id: null });
+            }
+        } catch (err) {
+            const localRow = dirtyLocal.find((r) => r.sync_id === syncId);
+            if (localRow) {
+                await putLocal({ ...localRow, _dirty: true, _pending_conflict_id: conflict.id });
+            }
+        }
+    }
+}
+
+// Returns true if locally-queued offline changes were successfully pushed up
+// this call - meaning the current (server-rendered) page was rendered before
+// those changes existed and is now stale, so the caller should refresh it.
+// Returns false if there was nothing to push, or the sync didn't complete.
+async function runBackgroundSync() {
+    const csrfToken = getCsrfToken();
+    if (!csrfToken) {
+        return false; // Not on an authenticated page (e.g. login/register).
+    }
+
+    const deviceId = await ensureDeviceId();
+    const syncFormatVersion = await getMeta('sync_format_version');
+    const forceFullResync = (syncFormatVersion || 1) < SYNC_FORMAT_VERSION;
+    const lastSyncToken = forceFullResync ? null : await getMeta('last_sync_token');
+
+    const dirtyTasks = await getDirtyTasks();
+    const dirtyTags = await getDirtyTags();
+    const dirtyTimeEntries = await getDirtyTimeEntries();
+    const hadPendingChanges = dirtyTasks.length + dirtyTags.length + dirtyTimeEntries.length > 0;
+
+    let response;
+    try {
+        response = await fetch('/api/sync/', {
+            method: 'POST',
+            headers: {
+                'Content-Type': 'application/json',
+                'X-CSRFToken': csrfToken,
+            },
+            body: JSON.stringify({
+                device_id: deviceId,
+                last_sync_token: lastSyncToken || null,
+                changes: {
+                    tasks: dirtyTasks.map(stripLocalFields),
+                    tags: dirtyTags.map(stripLocalFields),
+                    time_entries: dirtyTimeEntries.map(timeEntryToWire),
+                },
+            }),
+        });
+    } catch (err) {
+        return false; // Offline or network error - retry next time, nothing to clean up.
+    }
+
+    if (!response.ok) {
+        return false; // Includes 429 throttled - retry next time.
+    }
+
+    const data = await response.json();
+    const conflicts = data.conflicts || [];
+
+    await mergeAndResolveEntity({
+        entityType: 'task', dirtyLocal: dirtyTasks, serverRows: data.server_changes.tasks,
+        conflicts, csrfToken, putLocal: putLocalTask,
+    });
+    await mergeAndResolveEntity({
+        entityType: 'tag', dirtyLocal: dirtyTags, serverRows: data.server_changes.tags,
+        conflicts, csrfToken, putLocal: putLocalTag,
+    });
+    await mergeAndResolveEntity({
+        entityType: 'time_entry', dirtyLocal: dirtyTimeEntries, serverRows: data.server_changes.time_entries,
+        conflicts, csrfToken, putLocal: putLocalTimeEntry, fromWire: timeEntryFromWire,
+    });
+
+    await setMeta('last_sync_token', data.sync_token);
+    await setMeta('last_sync_at', new Date().toISOString());
+    await setMeta('sync_format_version', SYNC_FORMAT_VERSION);
+
+    // A forced full resync just backfilled previously-missed data (e.g. tags
+    // that existed before tag syncing shipped) - worth a refresh even if
+    // nothing local was dirty, since the current page may be missing it too.
+    return hadPendingChanges || forceFullResync;
+}
+

static/js/offline-tasks.js

@@ -0,0 +1,797 @@
+/**
+ * KeepItGoing - Offline mini task app
+ * Renders and edits tasks straight from IndexedDB while there's no network.
+ * Reuses .task-item/.task-checkbox/.priority-badge/.task-group-label/.modal-*
+ * classes from the real app's templates for visual consistency, and mirrors
+ * the dashboard's default filter/sort (tasks/views.py DashboardView) and the
+ * task-detail view's fields/actions (templates/tasks/_task_detail.html).
+ */
+
+const PRIORITY_ORDER = { urgent: 4, high: 3, medium: 2, low: 1 };
+const RECURRENCE_CHOICES = ['none', 'daily', 'weekly', 'biweekly', 'monthly', 'yearly'];
+const TAG_COLOR_PRESETS = ['#3b82f6', '#ef4444', '#10b981', '#f59e0b', '#8b5cf6', '#ec4899', '#06b6d4', '#84cc16'];
+
+let currentFilter = 'all';
+let currentSort = 'due_date';
+let currentTagId = null;
+let openTaskSyncId = null;
+let timerDisplayInterval = null;
+let currentTagModalSyncId = null;
+
+/* ============================================
+   Date/format helpers
+   ============================================ */
+
+function todayLocalStr() {
+    const d = new Date();
+    const y = d.getFullYear();
+    const m = String(d.getMonth() + 1).padStart(2, '0');
+    const day = String(d.getDate()).padStart(2, '0');
+    return `${y}-${m}-${day}`;
+}
+
+function formatDueDate(dateStr) {
+    if (!dateStr) return '';
+    const date = new Date(dateStr + 'T00:00:00');
+    return date.toLocaleDateString(undefined, { month: 'short', day: 'numeric', year: 'numeric' });
+}
+
+function formatDuration(totalSeconds) {
+    const seconds = Math.max(0, totalSeconds || 0);
+    const hours = Math.floor(seconds / 3600);
+    const minutes = Math.floor((seconds % 3600) / 60);
+    const secs = seconds % 60;
+    return `${hours}:${String(minutes).padStart(2, '0')}:${String(secs).padStart(2, '0')}`;
+}
+
+/* ============================================
+   Filter/sort (mirrors DashboardView's defaults)
+   ============================================ */
+
+function applyFilter(tasks, filter) {
+    const today = todayLocalStr();
+    if (filter === 'completed') {
+        return tasks.filter((t) => t.status === 'completed');
+    }
+    const notCompleted = tasks.filter((t) => t.status !== 'completed');
+    switch (filter) {
+        case 'today':
+            return notCompleted.filter((t) => t.due_date === today);
+        case 'upcoming':
+            return notCompleted.filter((t) => t.due_date && t.due_date > today);
+        case 'overdue':
+            return notCompleted.filter((t) => t.due_date && t.due_date < today && t.status !== 'cancelled');
+        default:
+            return notCompleted;
+    }
+}
+
+function applyTagFilter(tasks, tagId) {
+    if (!tagId) return tasks;
+    return tasks.filter((t) => (t.tag_sync_ids || []).includes(tagId));
+}
+
+function applySort(tasks, sort) {
+    const sorted = [...tasks];
+    const dueOrDefault = (t) => t.due_date || '9999-99-99';
+    const priorityOf = (t) => PRIORITY_ORDER[t.priority] || 0;
+
+    switch (sort) {
+        case 'due_date_desc':
+            sorted.sort((a, b) => dueOrDefault(b).localeCompare(dueOrDefault(a)) || priorityOf(b) - priorityOf(a));
+            break;
+        case 'priority':
+            sorted.sort((a, b) => priorityOf(b) - priorityOf(a) || dueOrDefault(a).localeCompare(dueOrDefault(b)));
+            break;
+        case 'priority_low':
+            sorted.sort((a, b) => priorityOf(a) - priorityOf(b) || dueOrDefault(a).localeCompare(dueOrDefault(b)));
+            break;
+        case 'due_date':
+        default:
+            sorted.sort((a, b) => dueOrDefault(a).localeCompare(dueOrDefault(b)) || priorityOf(b) - priorityOf(a));
+            break;
+    }
+    return sorted;
+}
+
+/* ============================================
+   Task list rendering
+   ============================================ */
+
+function renderTagChips(task, tagsBySyncId) {
+    const tagIds = task.tag_sync_ids || [];
+    if (tagIds.length === 0) return '';
+    return tagIds
+        .map((id) => tagsBySyncId[id])
+        .filter(Boolean)
+        .map((tag) => `<span class="task-group-label" style="background-color: ${tag.color}; color: white; font-weight: 600;">${escapeHtml(tag.name)}</span>`)
+        .join('');
+}
+
+function escapeHtml(str) {
+    const div = document.createElement('div');
+    div.textContent = str == null ? '' : String(str);
+    return div.innerHTML;
+}
+
+function isTaskOverdue(task) {
+    // Mirrors Task.is_overdue in tasks/models.py.
+    if (!task.due_date || task.status === 'completed' || task.status === 'cancelled') return false;
+    const today = todayLocalStr();
+    if (task.due_date < today) return true;
+    if (task.due_date === today && task.due_time) {
+        const now = new Date();
+        const nowStr = `${String(now.getHours()).padStart(2, '0')}:${String(now.getMinutes()).padStart(2, '0')}:${String(now.getSeconds()).padStart(2, '0')}`;
+        return task.due_time < nowStr;
+    }
+    return false;
+}
+
+function renderTaskItem(task, tagsBySyncId) {
+    const overdue = isTaskOverdue(task);
+    const item = document.createElement('div');
+    item.className = `task-item priority-${task.priority}${overdue ? ' overdue' : ''}${task.status === 'completed' ? ' completed' : ''}`;
+
+    const toggleForm = document.createElement('button');
+    toggleForm.type = 'button';
+    toggleForm.className = `task-checkbox${task.status === 'completed' ? ' checked' : ''}`;
+    toggleForm.setAttribute('aria-label', 'Toggle complete');
+    if (task.status === 'completed') {
+        toggleForm.innerHTML = '<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="3"><path d="M5 13l4 4L19 7"/></svg>';
+    }
+    toggleForm.addEventListener('click', (e) => {
+        e.stopPropagation();
+        toggleTaskComplete(task.sync_id);
+    });
+
+    const content = document.createElement('div');
+    content.className = 'task-content';
+
+    const title = document.createElement('div');
+    title.className = 'task-title';
+    title.textContent = task.title;
+    content.appendChild(title);
+
+    const metaParts = [];
+    if (task.due_date) {
+        metaParts.push(`<span class="task-due${overdue ? ' overdue' : ''}">📅 ${formatDueDate(task.due_date)}</span>`);
+    }
+    const tagChips = renderTagChips(task, tagsBySyncId);
+    if (metaParts.length || tagChips) {
+        const meta = document.createElement('div');
+        meta.className = 'task-meta';
+        meta.innerHTML = metaParts.join(' ') + tagChips;
+        content.appendChild(meta);
+    }
+
+    const priorityBadge = document.createElement('span');
+    priorityBadge.className = `priority-badge ${task.priority}`;
+    priorityBadge.textContent = task.priority;
+
+    item.appendChild(toggleForm);
+    item.appendChild(content);
+    item.appendChild(priorityBadge);
+
+    item.addEventListener('click', () => openTaskDetail(task.sync_id));
+
+    return item;
+}
+
+async function toggleTaskComplete(syncId) {
+    const tasks = await getAllTasks();
+    const task = tasks.find((t) => t.sync_id === syncId);
+    if (!task) return;
+
+    task.status = task.status === 'completed' ? 'pending' : 'completed';
+    task.updated_at = new Date().toISOString();
+    task._dirty = true;
+    await putLocalTask(task);
+    renderOfflineTasks();
+    if (openTaskSyncId === syncId) {
+        openTaskDetail(syncId);
+    }
+}
+
+function blankTask(overrides) {
+    const now = new Date().toISOString();
+    const syncId = crypto.randomUUID();
+    return {
+        id: syncId,
+        sync_id: syncId,
+        parent: null,
+        parent_sync_id: null,
+        title: '',
+        description: '',
+        status: 'pending',
+        priority: 'medium',
+        due_date: null,
+        due_time: null,
+        reminder_at: null,
+        recurrence: 'none',
+        recurrence_rule: '',
+        recurrence_end_date: null,
+        tag_sync_ids: [],
+        sort_order: 0,
+        is_deleted: false,
+        created_at: now,
+        updated_at: now,
+        _dirty: true,
+        _pending_conflict_id: null,
+        ...overrides,
+    };
+}
+
+async function addOfflineTask(title) {
+    await putLocalTask(blankTask({ title }));
+    renderOfflineTasks();
+}
+
+async function renderOfflineTasks() {
+    const listEl = document.getElementById('offline-task-list');
+    const emptyEl = document.getElementById('offline-empty-state');
+    if (!listEl) return;
+
+    const [allTasks, allTags] = await Promise.all([getAllTasks(), getAllTags()]);
+    const tagsBySyncId = {};
+    allTags.forEach((t) => { if (!t.is_deleted) tagsBySyncId[t.sync_id] = t; });
+
+    // Only top-level tasks in the main list - subtasks appear inside their
+    // parent's detail modal, matching the online dashboard.
+    const topLevel = allTasks.filter((t) => !t.is_deleted && !t.parent_sync_id);
+    const statusFiltered = applyFilter(topLevel, currentFilter);
+    const visibleTasks = applySort(applyTagFilter(statusFiltered, currentTagId), currentSort);
+
+    setActiveFilterNav(currentFilter);
+    renderTagSidebarNav(allTags, topLevel);
+
+    const titleEl = document.getElementById('offline-page-title');
+    if (titleEl) {
+        const tagName = currentTagId && tagsBySyncId[currentTagId] ? tagsBySyncId[currentTagId].name : null;
+        titleEl.textContent = (FILTER_TITLES[currentFilter] || 'All Tasks') + (tagName ? ` • ${tagName}` : '');
+    }
+
+    listEl.innerHTML = '';
+
+    if (visibleTasks.length === 0) {
+        const lastSyncToken = await getMeta('last_sync_token');
+        emptyEl.textContent = lastSyncToken
+            ? 'No tasks here.'
+            : "No offline data yet — connect once while online to sync your tasks.";
+        emptyEl.hidden = false;
+        listEl.hidden = true;
+        return;
+    }
+
+    emptyEl.hidden = true;
+    listEl.hidden = false;
+    for (const task of visibleTasks) {
+        listEl.appendChild(renderTaskItem(task, tagsBySyncId));
+    }
+}
+
+const FILTER_TITLES = { all: 'All Tasks', today: 'Today', upcoming: 'Upcoming', overdue: 'Overdue', completed: 'Completed' };
+
+function setActiveFilterNav(filter) {
+    document.querySelectorAll('#offline-filter-nav .sidebar-item').forEach((item) => {
+        item.classList.toggle('active', item.dataset.filter === filter);
+    });
+}
+
+/* ============================================
+   Sidebar Tags section (filter-by-tag + manage)
+   ============================================ */
+
+function renderTagSidebarNav(allTags, topLevelTasks) {
+    const nav = document.getElementById('offline-tag-nav');
+    if (!nav) return;
+
+    const visibleTags = allTags.filter((t) => !t.is_deleted && !t.is_archived);
+    // Counts match the sidebar Filters' "all" semantics: top-level, not completed.
+    const countable = topLevelTasks.filter((t) => t.status !== 'completed');
+
+    nav.innerHTML = visibleTags.map((tag) => {
+        const count = countable.filter((t) => (t.tag_sync_ids || []).includes(tag.sync_id)).length;
+        return `
+            <div class="sidebar-group-row">
+                <a href="#" class="sidebar-item sidebar-group-item ${currentTagId === tag.sync_id ? 'active' : ''}" data-tag-id="${tag.sync_id}">
+                    <span class="group-color-dot" style="background-color: ${tag.color}"></span>
+                    ${escapeHtml(tag.name)}
+                    ${count ? `<span class="sidebar-item-count">${count}</span>` : ''}
+                </a>
+                <button type="button" class="sidebar-group-edit" title="Edit tag" data-edit-tag-id="${tag.sync_id}">
+                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                        <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"/>
+                        <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"/>
+                    </svg>
+                </button>
+            </div>
+        `;
+    }).join('') + `
+        <a href="#" class="sidebar-item sidebar-group-item ${!currentTagId ? 'active' : ''}" id="offline-all-tags-link">
+            <span class="group-color-dot" style="background-color: var(--text-muted)"></span>
+            All Tags
+        </a>
+    `;
+
+    nav.querySelectorAll('.sidebar-group-item[data-tag-id]').forEach((link) => {
+        link.addEventListener('click', (e) => {
+            e.preventDefault();
+            currentTagId = link.dataset.tagId;
+            renderOfflineTasks();
+        });
+    });
+    nav.querySelectorAll('.sidebar-group-edit').forEach((btn) => {
+        btn.addEventListener('click', (e) => {
+            e.preventDefault();
+            e.stopPropagation();
+            const tag = visibleTags.find((t) => t.sync_id === btn.dataset.editTagId);
+            if (tag) openTagModal(tag.sync_id, tag.name, tag.color);
+        });
+    });
+    const allTagsLink = document.getElementById('offline-all-tags-link');
+    if (allTagsLink) {
+        allTagsLink.addEventListener('click', (e) => {
+            e.preventDefault();
+            currentTagId = null;
+            renderOfflineTasks();
+        });
+    }
+}
+
+function renderTagColorPresets(selectedColor) {
+    const container = document.getElementById('tag-modal-color-presets');
+    if (!container) return;
+    container.innerHTML = TAG_COLOR_PRESETS.map((c) => `
+        <button type="button" class="color-preset ${c.toLowerCase() === selectedColor.toLowerCase() ? 'selected' : ''}" data-color="${c}" style="background-color: ${c}"></button>
+    `).join('');
+    container.querySelectorAll('.color-preset').forEach((btn) => {
+        btn.addEventListener('click', () => {
+            document.getElementById('tag-modal-color').value = btn.dataset.color;
+            container.querySelectorAll('.color-preset').forEach((b) => b.classList.toggle('selected', b === btn));
+        });
+    });
+}
+
+function openTagModal(tagSyncId = null, name = '', color = '#3b82f6') {
+    currentTagModalSyncId = tagSyncId;
+    document.getElementById('tag-modal-title').textContent = tagSyncId ? 'Edit Tag' : 'New Tag';
+    document.getElementById('tag-modal-name').value = name;
+    document.getElementById('tag-modal-color').value = color;
+    document.getElementById('tag-modal-submit-btn').textContent = tagSyncId ? 'Save' : 'Create';
+    document.getElementById('tag-modal-delete-btn').style.display = tagSyncId ? 'inline-flex' : 'none';
+    renderTagColorPresets(color);
+    document.getElementById('tag-modal-backdrop').classList.add('open');
+    document.getElementById('tag-modal-name').focus();
+}
+
+function closeTagModal() {
+    document.getElementById('tag-modal-backdrop').classList.remove('open');
+    currentTagModalSyncId = null;
+}
+
+async function saveTagModal() {
+    const name = document.getElementById('tag-modal-name').value.trim();
+    if (!name) return;
+    const color = document.getElementById('tag-modal-color').value;
+    const now = new Date().toISOString();
+
+    if (currentTagModalSyncId) {
+        const tags = await getAllTags();
+        const tag = tags.find((t) => t.sync_id === currentTagModalSyncId);
+        if (tag) {
+            tag.name = name;
+            tag.color = color;
+            tag.updated_at = now;
+            tag._dirty = true;
+            await putLocalTag(tag);
+        }
+    } else {
+        const syncId = crypto.randomUUID();
+        await putLocalTag({
+            id: syncId, sync_id: syncId, name, description: '', color, icon: '',
+            sort_order: 0, is_archived: false, is_deleted: false,
+            created_at: now, updated_at: now, _dirty: true, _pending_conflict_id: null,
+        });
+    }
+
+    closeTagModal();
+    renderOfflineTasks();
+    if (openTaskSyncId) {
+        renderTaskDetailPane();
+    }
+}
+
+async function deleteCurrentTag() {
+    if (!currentTagModalSyncId) return;
+    if (!confirm('Are you sure you want to delete this tag?\n\nTasks with this tag will not be deleted.')) {
+        return;
+    }
+    const tags = await getAllTags();
+    const tag = tags.find((t) => t.sync_id === currentTagModalSyncId);
+    if (tag) {
+        tag.is_deleted = true;
+        tag.updated_at = new Date().toISOString();
+        tag._dirty = true;
+        await putLocalTag(tag);
+    }
+    if (currentTagId === currentTagModalSyncId) {
+        currentTagId = null;
+    }
+    closeTagModal();
+    renderOfflineTasks();
+}
+
+/* ============================================
+   Task detail pane
+   (internal element ids keep the "modal-" prefix from an earlier design,
+   but this now renders into the real #detail-pane, matching the online
+   dashboard's slide-in panel instead of a popup modal.)
+   ============================================ */
+
+function closeTaskDetail() {
+    document.getElementById('detail-pane').classList.add('hidden');
+    document.getElementById('app').classList.add('detail-closed');
+    closeOfflineMobileMenus();
+    stopTimerDisplayInterval();
+    openTaskSyncId = null;
+}
+
+async function openTaskDetail(syncId) {
+    openTaskSyncId = syncId;
+    await renderTaskDetailPane();
+    const detailPane = document.getElementById('detail-pane');
+    detailPane.classList.remove('hidden');
+    document.getElementById('app').classList.remove('detail-closed');
+    if (window.innerWidth <= 1024) {
+        detailPane.classList.add('open');
+        document.getElementById('mobile-overlay').classList.add('visible');
+    }
+}
+
+async function renderTaskDetailPane() {
+    const syncId = openTaskSyncId;
+    if (!syncId) return;
+
+    const [allTasks, allTags, allTimeEntries] = await Promise.all([
+        getAllTasks(), getAllTags(), getAllTimeEntries(),
+    ]);
+    const task = allTasks.find((t) => t.sync_id === syncId);
+    if (!task) {
+        closeTaskDetail();
+        return;
+    }
+
+    const tags = allTags.filter((t) => !t.is_deleted);
+    const subtasks = allTasks.filter((t) => !t.is_deleted && t.parent_sync_id === syncId);
+    const taskTimeEntries = allTimeEntries.filter((e) => !e.is_deleted && e.task_sync_id === syncId);
+    const totalSeconds = taskTimeEntries.reduce((sum, e) => sum + (e.duration_seconds || 0), 0);
+    const runningEntry = taskTimeEntries.find((e) => !e.ended_at);
+
+    const body = document.getElementById('detail-pane');
+    body.innerHTML = `
+        <div class="detail-header">
+            <h2 style="font-size: var(--font-lg); font-weight: 600;">Task Details</h2>
+            <button class="detail-close" id="detail-close-btn" aria-label="Close detail panel">
+                <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <path d="M18 6L6 18M6 6l12 12"/>
+                </svg>
+            </button>
+        </div>
+        <form id="task-edit-form">
+            <div class="form-group">
+                <label class="form-label" for="modal-title">Title</label>
+                <input type="text" class="form-input" id="modal-title" required value="${escapeHtml(task.title)}">
+            </div>
+            <div class="form-group">
+                <label class="form-label" for="modal-description">Description</label>
+                <textarea class="form-textarea" id="modal-description" rows="3">${escapeHtml(task.description)}</textarea>
+            </div>
+            <div class="form-row">
+                <div class="form-group">
+                    <label class="form-label" for="modal-status">Status</label>
+                    <select class="form-select" id="modal-status">
+                        <option value="pending" ${task.status === 'pending' ? 'selected' : ''}>Pending</option>
+                        <option value="in_progress" ${task.status === 'in_progress' ? 'selected' : ''}>In Progress</option>
+                        <option value="completed" ${task.status === 'completed' ? 'selected' : ''}>Completed</option>
+                        <option value="cancelled" ${task.status === 'cancelled' ? 'selected' : ''}>Cancelled</option>
+                    </select>
+                </div>
+                <div class="form-group">
+                    <label class="form-label" for="modal-priority">Priority</label>
+                    <select class="form-select" id="modal-priority">
+                        <option value="low" ${task.priority === 'low' ? 'selected' : ''}>Low</option>
+                        <option value="medium" ${task.priority === 'medium' ? 'selected' : ''}>Medium</option>
+                        <option value="high" ${task.priority === 'high' ? 'selected' : ''}>High</option>
+                        <option value="urgent" ${task.priority === 'urgent' ? 'selected' : ''}>Urgent</option>
+                    </select>
+                </div>
+            </div>
+            <div class="form-row">
+                <div class="form-group">
+                    <label class="form-label" for="modal-due-date">Due Date</label>
+                    <input type="date" class="form-input" id="modal-due-date" value="${task.due_date || ''}">
+                </div>
+                <div class="form-group">
+                    <label class="form-label" for="modal-due-time">Due Time</label>
+                    <input type="time" class="form-input" id="modal-due-time" value="${task.due_time || ''}">
+                </div>
+            </div>
+            <div class="form-row">
+                <div class="form-group">
+                    <label class="form-label" for="modal-recurrence">Recurrence</label>
+                    <select class="form-select" id="modal-recurrence">
+                        ${RECURRENCE_CHOICES.map((r) => `<option value="${r}" ${task.recurrence === r ? 'selected' : ''}>${r === 'none' ? 'None' : r.charAt(0).toUpperCase() + r.slice(1)}</option>`).join('')}
+                    </select>
+                </div>
+                <div class="form-group">
+                    <label class="form-label" for="modal-recurrence-end">Ends</label>
+                    <input type="date" class="form-input" id="modal-recurrence-end" value="${task.recurrence_end_date || ''}">
+                </div>
+            </div>
+            <div class="form-group">
+                <label class="form-label">Tags</label>
+                <div id="modal-tag-checkboxes" style="display: flex; flex-wrap: wrap; gap: var(--space-sm); margin-bottom: var(--space-sm);">
+                    ${tags.map((tag) => `
+                        <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                            <input type="checkbox" class="modal-tag-checkbox" value="${tag.sync_id}" ${(task.tag_sync_ids || []).includes(tag.sync_id) ? 'checked' : ''}>
+                            <span style="color: ${tag.color}">${escapeHtml(tag.name)}</span>
+                        </label>
+                    `).join('') || '<span class="text-muted">No tags yet.</span>'}
+                </div>
+                <div style="display: flex; gap: var(--space-sm);">
+                    <input type="text" id="modal-new-tag-name" class="form-input" placeholder="New tag name" style="flex: 1;">
+                    <input type="color" id="modal-new-tag-color" value="${TAG_COLOR_PRESETS[0]}" style="width: 40px; padding: 2px;">
+                    <button type="button" class="btn btn-secondary btn-sm" id="modal-add-tag-btn">+ Tag</button>
+                </div>
+            </div>
+            <button type="submit" class="btn btn-primary" style="width: 100%;">Save</button>
+        </form>
+
+        <div style="margin-top: var(--space-lg); background: var(--bg); border-radius: var(--radius-sm); padding: var(--space-md);">
+            <div style="font-size: var(--font-sm); font-weight: 500; color: var(--text-secondary); margin-bottom: var(--space-sm);">Subtasks</div>
+            <form id="modal-subtask-form" style="display: flex; gap: var(--space-sm); margin-bottom: var(--space-sm);">
+                <input type="text" id="modal-subtask-title" class="form-input" placeholder="Add a subtask..." style="flex: 1; padding: var(--space-xs) var(--space-sm); font-size: var(--font-sm);" required>
+                <button type="submit" class="btn btn-primary btn-sm">Add</button>
+            </form>
+            <div id="modal-subtask-list" style="display: flex; flex-direction: column; gap: var(--space-xs);">
+                ${subtasks.length === 0 ? '<div style="font-size: var(--font-sm); color: var(--text-muted);">No subtasks</div>' : subtasks.map((st) => `
+                    <div style="display: flex; align-items: center; gap: var(--space-sm); padding: var(--space-xs); border-radius: var(--radius-xs); background: var(--surface);">
+                        <button type="button" class="task-checkbox modal-subtask-toggle ${st.status === 'completed' ? 'checked' : ''}" data-sync-id="${st.sync_id}" style="width: 16px; height: 16px; font-size: 10px;">${st.status === 'completed' ? '&#10003;' : ''}</button>
+                        <span style="font-size: var(--font-sm); ${st.status === 'completed' ? 'text-decoration: line-through; color: var(--text-muted);' : ''}">${escapeHtml(st.title)}</span>
+                    </div>
+                `).join('')}
+            </div>
+        </div>
+
+        <div class="time-tracker" style="margin-top: var(--space-lg);">
+            <div class="time-tracker-header">
+                <span class="time-tracker-label">Time Spent</span>
+                <span class="time-tracker-total" id="modal-time-total">${formatDuration(totalSeconds)}</span>
+            </div>
+            <div style="display: flex; gap: var(--space-sm); margin-top: var(--space-sm);">
+                ${runningEntry
+                    ? `<button type="button" class="btn btn-danger btn-full btn-sm" id="modal-timer-btn" data-running="true" data-entry-sync-id="${runningEntry.sync_id}" data-started="${runningEntry.started_at}">Stop Timer</button>`
+                    : `<button type="button" class="btn btn-secondary btn-full btn-sm" id="modal-timer-btn" data-running="false">Start Timer</button>`
+                }
+            </div>
+        </div>
+    `;
+
+    wireModalEvents(task, totalSeconds);
+}
+
+function wireModalEvents(task, baseTotalSeconds) {
+    document.getElementById('detail-close-btn').addEventListener('click', closeTaskDetail);
+
+    document.getElementById('task-edit-form').addEventListener('submit', (e) => {
+        e.preventDefault();
+        saveTaskModalEdits(task.sync_id);
+    });
+
+    document.getElementById('modal-add-tag-btn').addEventListener('click', () => {
+        addNewTagInline(task.sync_id);
+    });
+
+    document.getElementById('modal-subtask-form').addEventListener('submit', (e) => {
+        e.preventDefault();
+        const input = document.getElementById('modal-subtask-title');
+        const title = input.value.trim();
+        if (title) {
+            addOfflineSubtask(task.sync_id, title);
+        }
+    });
+
+    document.querySelectorAll('.modal-subtask-toggle').forEach((btn) => {
+        btn.addEventListener('click', () => toggleTaskComplete(btn.dataset.syncId));
+    });
+
+    const timerBtn = document.getElementById('modal-timer-btn');
+    timerBtn.addEventListener('click', () => {
+        if (timerBtn.dataset.running === 'true') {
+            stopTimer(timerBtn.dataset.entrySyncId, task.sync_id);
+        } else {
+            startTimer(task.sync_id);
+        }
+    });
+
+    stopTimerDisplayInterval();
+    if (timerBtn.dataset.running === 'true') {
+        const startedAt = new Date(timerBtn.dataset.started).getTime();
+        timerDisplayInterval = setInterval(() => {
+            const liveSeconds = baseTotalSeconds + Math.floor((Date.now() - startedAt) / 1000);
+            const totalEl = document.getElementById('modal-time-total');
+            if (totalEl) totalEl.textContent = formatDuration(liveSeconds);
+        }, 1000);
+    }
+}
+
+function stopTimerDisplayInterval() {
+    if (timerDisplayInterval) {
+        clearInterval(timerDisplayInterval);
+        timerDisplayInterval = null;
+    }
+}
+
+async function saveTaskModalEdits(syncId) {
+    const tasks = await getAllTasks();
+    const task = tasks.find((t) => t.sync_id === syncId);
+    if (!task) return;
+
+    task.title = document.getElementById('modal-title').value.trim() || task.title;
+    task.description = document.getElementById('modal-description').value;
+    task.status = document.getElementById('modal-status').value;
+    task.priority = document.getElementById('modal-priority').value;
+    task.due_date = document.getElementById('modal-due-date').value || null;
+    task.due_time = document.getElementById('modal-due-time').value || null;
+    task.recurrence = document.getElementById('modal-recurrence').value;
+    task.recurrence_end_date = document.getElementById('modal-recurrence-end').value || null;
+    task.tag_sync_ids = Array.from(document.querySelectorAll('.modal-tag-checkbox:checked')).map((cb) => cb.value);
+    task.updated_at = new Date().toISOString();
+    task._dirty = true;
+
+    await putLocalTask(task);
+    closeTaskDetail();
+    renderOfflineTasks();
+}
+
+async function addNewTagInline(taskSyncId) {
+    const nameInput = document.getElementById('modal-new-tag-name');
+    const colorInput = document.getElementById('modal-new-tag-color');
+    const name = nameInput.value.trim();
+    if (!name) return;
+
+    const now = new Date().toISOString();
+    const syncId = crypto.randomUUID();
+    await putLocalTag({
+        id: syncId, sync_id: syncId, name, description: '', color: colorInput.value,
+        icon: '', sort_order: 0, is_archived: false, is_deleted: false,
+        created_at: now, updated_at: now, _dirty: true, _pending_conflict_id: null,
+    });
+    nameInput.value = '';
+    await renderTaskDetailPane();
+}
+
+async function addOfflineSubtask(parentSyncId, title) {
+    const tasks = await getAllTasks();
+    const parent = tasks.find((t) => t.sync_id === parentSyncId);
+    const subtask = blankTask({
+        title,
+        parent: parentSyncId,
+        parent_sync_id: parentSyncId,
+        // Subtasks inherit the parent's tags, matching tasks/views.py subtask_create.
+        tag_sync_ids: parent ? [...(parent.tag_sync_ids || [])] : [],
+    });
+    await putLocalTask(subtask);
+    await renderTaskDetailPane();
+}
+
+async function startTimer(taskSyncId) {
+    const running = await getRunningTimeEntry();
+    if (running) {
+        // Only one timer can run per user at a time, matching web_timer_start.
+        running.ended_at = new Date().toISOString();
+        running.duration_seconds = Math.round((new Date(running.ended_at) - new Date(running.started_at)) / 1000);
+        running._dirty = true;
+        await putLocalTimeEntry(running);
+    }
+
+    const now = new Date().toISOString();
+    const syncId = crypto.randomUUID();
+    await putLocalTimeEntry({
+        id: syncId, sync_id: syncId, task_sync_id: taskSyncId, started_at: now, ended_at: null,
+        duration_seconds: null, notes: '', is_deleted: false, created_at: now, updated_at: now,
+        _dirty: true, _pending_conflict_id: null,
+    });
+    await renderTaskDetailPane();
+}
+
+async function stopTimer(entrySyncId) {
+    const entries = await getAllTimeEntries();
+    const entry = entries.find((e) => e.sync_id === entrySyncId);
+    if (!entry) return;
+
+    entry.ended_at = new Date().toISOString();
+    entry.duration_seconds = Math.round((new Date(entry.ended_at) - new Date(entry.started_at)) / 1000);
+    entry.updated_at = entry.ended_at;
+    entry._dirty = true;
+    await putLocalTimeEntry(entry);
+    await renderTaskDetailPane();
+}
+
+/* ============================================
+   Init
+   ============================================ */
+
+document.addEventListener('DOMContentLoaded', () => {
+    renderOfflineTasks();
+
+    const form = document.getElementById('offline-add-task-form');
+    if (form) {
+        form.addEventListener('submit', (event) => {
+            event.preventDefault();
+            const input = document.getElementById('offline-task-title');
+            const title = input.value.trim();
+            if (title) {
+                addOfflineTask(title);
+                input.value = '';
+            }
+        });
+    }
+
+    document.querySelectorAll('#offline-filter-nav .sidebar-item').forEach((item) => {
+        item.addEventListener('click', (e) => {
+            e.preventDefault();
+            currentFilter = item.dataset.filter;
+            renderOfflineTasks();
+        });
+    });
+
+    const sortSelect = document.getElementById('offline-sort-select');
+    if (sortSelect) {
+        sortSelect.value = currentSort;
+        sortSelect.addEventListener('change', () => {
+            currentSort = sortSelect.value;
+            renderOfflineTasks();
+        });
+    }
+
+    document.getElementById('offline-add-tag-btn').addEventListener('click', () => openTagModal());
+    document.getElementById('tag-modal-close-btn').addEventListener('click', closeTagModal);
+    document.getElementById('tag-modal-cancel-btn').addEventListener('click', closeTagModal);
+    document.getElementById('tag-modal-delete-btn').addEventListener('click', deleteCurrentTag);
+    document.getElementById('tag-edit-form').addEventListener('submit', (e) => {
+        e.preventDefault();
+        saveTagModal();
+    });
+    document.getElementById('tag-modal-backdrop').addEventListener('click', (e) => {
+        if (e.target.id === 'tag-modal-backdrop') {
+            closeTagModal();
+        }
+    });
+});
+
+/* ============================================
+   Sidebar / mobile chrome
+   (app.js isn't loaded on this self-contained offline page, so these
+   mirror its toggleSidebar()/closeMobileMenus()/toggleTheme() directly.)
+   ============================================ */
+
+function toggleOfflineSidebar() {
+    const sidebar = document.getElementById('sidebar');
+    const overlay = document.getElementById('mobile-overlay');
+    sidebar.classList.toggle('open');
+    overlay.classList.toggle('visible', sidebar.classList.contains('open'));
+}
+
+function closeOfflineMobileMenus() {
+    document.getElementById('sidebar').classList.remove('open');
+    document.getElementById('detail-pane').classList.remove('open');
+    document.getElementById('mobile-overlay').classList.remove('visible');
+}
+
+function toggleOfflineTheme() {
+    const current = document.documentElement.getAttribute('data-theme') || 'light';
+    const next = current === 'dark' ? 'light' : 'dark';
+    document.documentElement.setAttribute('data-theme', next);
+    localStorage.setItem('theme', next);
+}

sync/tests.py

@@ -1,3 +1,225 @@
-from django.test import TestCase
+import uuid
+from datetime import timedelta
 
-# Create your tests here.
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.utils import timezone
+from rest_framework.test import APIClient
+
+from tasks.models import Task, TimeEntry
+from sync.models import SyncLog, SyncConflict
+
+User = get_user_model()
+
+
+class SyncEndpointTests(TestCase):
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='synctestuser',
+            email='synctest@example.com',
+            password='testpass123',
+        )
+        self.client = APIClient()
+        self.client.force_authenticate(user=self.user)
+
+    def test_new_sync_id_creates_task(self):
+        new_sync_id = str(uuid.uuid4())
+        response = self.client.post('/api/sync/', {
+            'device_id': 'web-test-device',
+            'last_sync_token': None,
+            'changes': {
+                'tasks': [{
+                    'sync_id': new_sync_id,
+                    'title': 'Offline-created task',
+                    'status': 'pending',
+                    'priority': 'medium',
+                }],
+                'tags': [],
+                'time_entries': [],
+            },
+        }, format='json')
+
+        self.assertEqual(response.status_code, 200)
+        task = Task.objects.get(sync_id=new_sync_id)
+        self.assertEqual(task.title, 'Offline-created task')
+        self.assertEqual(task.user, self.user)
+
+    def test_is_deleted_soft_deletes_regardless_of_conflict(self):
+        task = Task.objects.create(user=self.user, title='To be deleted')
+
+        # Force a conflict window: server row touched after "last sync".
+        last_sync_at = timezone.now() - timedelta(minutes=5)
+        SyncLog.objects.create(
+            user=self.user, device_id='web-test-device',
+            sync_token='old-token', last_sync_at=last_sync_at,
+        )
+
+        response = self.client.post('/api/sync/', {
+            'device_id': 'web-test-device',
+            'last_sync_token': 'old-token',
+            'changes': {
+                'tasks': [{'sync_id': str(task.sync_id), 'is_deleted': True}],
+                'tags': [],
+                'time_entries': [],
+            },
+        }, format='json')
+
+        self.assertEqual(response.status_code, 200)
+        task.refresh_from_db()
+        self.assertTrue(task.is_deleted)
+        self.assertEqual(SyncConflict.objects.count(), 0)
+
+    def test_conflict_created_and_client_change_discarded(self):
+        task = Task.objects.create(user=self.user, title='Original title')
+
+        last_sync_at = timezone.now() - timedelta(minutes=5)
+        SyncLog.objects.create(
+            user=self.user, device_id='web-test-device',
+            sync_token='old-token', last_sync_at=last_sync_at,
+        )
+
+        # Server row modified after last_sync_at (updated_at auto-bumps on save).
+        task.title = 'Changed on server'
+        task.save()
+
+        response = self.client.post('/api/sync/', {
+            'device_id': 'web-test-device',
+            'last_sync_token': 'old-token',
+            'changes': {
+                'tasks': [{
+                    'sync_id': str(task.sync_id),
+                    'title': 'Changed offline',
+                    'status': 'pending',
+                }],
+                'tags': [],
+                'time_entries': [],
+            },
+        }, format='json')
+
+        self.assertEqual(response.status_code, 200)
+        data = response.json()
+        self.assertEqual(len(data['conflicts']), 1)
+        self.assertEqual(data['conflicts'][0]['local_data']['sync_id'], str(task.sync_id))
+
+        task.refresh_from_db()
+        self.assertEqual(task.title, 'Changed on server')
+
+    def test_resolve_conflict_local_applies_local_data(self):
+        task = Task.objects.create(user=self.user, title='Server title')
+        conflict = SyncConflict.objects.create(
+            user=self.user,
+            entity_type='task',
+            entity_id=task.id,
+            local_data={'sync_id': str(task.sync_id), 'title': 'Local title', 'status': 'pending'},
+            server_data={'title': 'Server title'},
+        )
+
+        response = self.client.post(
+            f'/api/sync/conflicts/{conflict.id}/resolve/',
+            {'resolution': 'local'},
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, 200)
+        task.refresh_from_db()
+        self.assertEqual(task.title, 'Local title')
+        conflict.refresh_from_db()
+        self.assertEqual(conflict.status, 'resolved_local')
+
+    def test_resolve_conflict_server_is_noop(self):
+        task = Task.objects.create(user=self.user, title='Server title')
+        conflict = SyncConflict.objects.create(
+            user=self.user,
+            entity_type='task',
+            entity_id=task.id,
+            local_data={'sync_id': str(task.sync_id), 'title': 'Local title'},
+            server_data={'title': 'Server title'},
+        )
+
+        response = self.client.post(
+            f'/api/sync/conflicts/{conflict.id}/resolve/',
+            {'resolution': 'server'},
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, 200)
+        task.refresh_from_db()
+        self.assertEqual(task.title, 'Server title')
+        conflict.refresh_from_db()
+        self.assertEqual(conflict.status, 'resolved_server')
+
+    def test_resolve_conflict_local_applies_time_entry_data(self):
+        task = Task.objects.create(user=self.user, title='Timed task')
+        start = timezone.now() - timedelta(hours=1)
+        entry = TimeEntry.objects.create(user=self.user, task=task, started_at=start, notes='server notes')
+        conflict = SyncConflict.objects.create(
+            user=self.user,
+            entity_type='time_entry',
+            entity_id=entry.id,
+            local_data={'sync_id': str(entry.sync_id), 'notes': 'local notes'},
+            server_data={'notes': 'server notes'},
+        )
+
+        response = self.client.post(
+            f'/api/sync/conflicts/{conflict.id}/resolve/',
+            {'resolution': 'local'},
+            format='json',
+        )
+
+        self.assertEqual(response.status_code, 200)
+        entry.refresh_from_db()
+        self.assertEqual(entry.notes, 'local notes')
+        conflict.refresh_from_db()
+        self.assertEqual(conflict.status, 'resolved_local')
+
+    def test_creating_task_with_due_date_and_time_does_not_crash(self):
+        """
+        Sync payloads carry due_date/due_time as JSON strings. Regression
+        test: these must end up as real date/time objects on the created
+        Task, not raw strings left for Task.reschedule_reminders() (called
+        from save()) to choke on.
+        """
+        new_sync_id = str(uuid.uuid4())
+        response = self.client.post('/api/sync/', {
+            'device_id': 'web-test-device',
+            'last_sync_token': None,
+            'changes': {
+                'tasks': [{
+                    'sync_id': new_sync_id,
+                    'title': 'Due-dated task',
+                    'status': 'pending',
+                    'priority': 'medium',
+                    'due_date': '2026-09-10',
+                    'due_time': '17:00:00',
+                }],
+                'tags': [],
+                'time_entries': [],
+            },
+        }, format='json')
+
+        self.assertEqual(response.status_code, 200)
+        task = Task.objects.get(sync_id=new_sync_id)
+        self.assertEqual(task.due_date.isoformat(), '2026-09-10')
+        self.assertEqual(task.due_time.isoformat(), '17:00:00')
+
+    def test_updating_task_due_date_and_time_does_not_crash(self):
+        task = Task.objects.create(user=self.user, title='Task to update')
+
+        response = self.client.post('/api/sync/', {
+            'device_id': 'web-test-device',
+            'last_sync_token': None,
+            'changes': {
+                'tasks': [{
+                    'sync_id': str(task.sync_id),
+                    'due_date': '2026-09-10',
+                    'due_time': '17:00:00',
+                }],
+                'tags': [],
+                'time_entries': [],
+            },
+        }, format='json')
+
+        self.assertEqual(response.status_code, 200)
+        task.refresh_from_db()
+        self.assertEqual(task.due_date.isoformat(), '2026-09-10')
+        self.assertEqual(task.due_time.isoformat(), '17:00:00')

sync/views.py

@@ -8,7 +8,7 @@ import logging
 import uuid
 from datetime import datetime
 from django.utils import timezone
-from django.utils.dateparse import parse_datetime
+from django.utils.dateparse import parse_date, parse_datetime, parse_time
 from rest_framework import status
 from rest_framework.decorators import api_view, permission_classes, throttle_classes
 from rest_framework.permissions import IsAuthenticated
@@ -289,19 +289,34 @@ def process_time_entry_changes(user, entry_changes, last_sync_at):
     return conflicts
 
 
+def _parsed(data, key, default, parser):
+    """Get data[key], parsing it if it's still a raw string (e.g. from JSON), else default if absent."""
+    if key not in data:
+        return default
+    value = data[key]
+    return parser(value) if isinstance(value, str) else value
+
+
 def update_task_from_data(task, data):
     """Update a task from sync data."""
+    # Track old status to detect completion
+    old_status = task.status
+
     task.title = data.get('title', task.title)
     task.description = data.get('description', task.description)
     task.status = data.get('status', task.status)
     task.priority = data.get('priority', task.priority)
-    task.due_date = data.get('due_date', task.due_date)
-    task.due_time = data.get('due_time', task.due_time)
-    task.reminder_at = data.get('reminder_at', task.reminder_at)
+    task.due_date = _parsed(data, 'due_date', task.due_date, parse_date)
+    task.due_time = _parsed(data, 'due_time', task.due_time, parse_time)
+    task.reminder_at = _parsed(data, 'reminder_at', task.reminder_at, parse_datetime)
     task.recurrence = data.get('recurrence', task.recurrence)
     task.recurrence_rule = data.get('recurrence_rule', task.recurrence_rule)
     task.sort_order = data.get('sort_order', task.sort_order)
 
+    # Create next recurrence if task is being marked as completed
+    if old_status != 'completed' and task.status == 'completed' and task.recurrence != 'none':
+        task.create_next_recurrence()
+
     task.save()
 
     # Handle tags
@@ -334,9 +349,9 @@ def create_task_from_data(user, data):
         description=data.get('description', ''),
         status=data.get('status', 'pending'),
         priority=data.get('priority', 'medium'),
-        due_date=data.get('due_date'),
-        due_time=data.get('due_time'),
-        reminder_at=data.get('reminder_at'),
+        due_date=_parsed(data, 'due_date', None, parse_date),
+        due_time=_parsed(data, 'due_time', None, parse_time),
+        reminder_at=_parsed(data, 'reminder_at', None, parse_datetime),
         recurrence=data.get('recurrence', 'none'),
         recurrence_rule=data.get('recurrence_rule', ''),
         sort_order=data.get('sort_order', 0),
@@ -467,3 +482,21 @@ def apply_conflict_data(entity_type, entity_id, data):
             tag.save()
         except Tag.DoesNotExist:
             pass
+    elif entity_type == 'time_entry':
+        try:
+            entry = TimeEntry.objects.get(id=entity_id)
+
+            started_at = data.get('started_at', entry.started_at)
+            if isinstance(started_at, str):
+                started_at = parse_datetime(started_at)
+
+            ended_at = data.get('ended_at', entry.ended_at)
+            if ended_at and isinstance(ended_at, str):
+                ended_at = parse_datetime(ended_at)
+
+            entry.started_at = started_at
+            entry.ended_at = ended_at
+            entry.notes = data.get('notes', entry.notes)
+            entry.save()
+        except TimeEntry.DoesNotExist:
+            pass

tasks/middleware/__init__.py

@@ -0,0 +1,3 @@
+from .mobile_app import AllowMobileAppFramingMiddleware
+
+__all__ = ['AllowMobileAppFramingMiddleware']

tasks/middleware/mobile_app.py

@@ -0,0 +1,61 @@
+"""
+Middleware to allow iframe embedding for the KeepItGoing mobile app.
+
+The mobile app uses Capacitor WebView which embeds the website in an iframe.
+This middleware detects requests from the mobile app and removes both
+X-Frame-Options and Content-Security-Policy frame-ancestors headers to allow
+iframe embedding, while keeping clickjacking protection for regular web browsers.
+"""
+
+
+class AllowMobileAppFramingMiddleware:
+    """
+    Remove frame-blocking headers for requests from KeepItGoing mobile app.
+
+    The mobile app uses a Capacitor WebView. We detect these requests via
+    User-Agent and remove X-Frame-Options and CSP frame-ancestors headers.
+    """
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+        response = self.get_response(request)
+
+        # Check if request is from KeepItGoing mobile app
+        user_agent = request.META.get('HTTP_USER_AGENT', '')
+
+        # Detect Capacitor/Android WebView patterns
+        is_mobile_app = (
+            'wv' in user_agent.lower() or  # Android WebView
+            'CapacitorHttp' in user_agent or
+            'com.firebugit.keepitgoing' in user_agent or
+            ('KeepItGoing' in user_agent and 'Mobile' in user_agent)
+        )
+
+        if is_mobile_app:
+            # Mobile app: Allow iframe embedding - don't add frame-blocking headers
+            # Remove any existing frame headers
+            if 'X-Frame-Options' in response:
+                del response['X-Frame-Options']
+            if 'Content-Security-Policy' in response:
+                del response['Content-Security-Policy']
+        else:
+            # Regular browsers: Add security headers for clickjacking protection
+            if 'X-Frame-Options' not in response:
+                response['X-Frame-Options'] = 'DENY'
+
+            if 'Content-Security-Policy' not in response:
+                response['Content-Security-Policy'] = (
+                    "default-src 'self'; "
+                    "script-src 'self' 'unsafe-inline'; "
+                    "style-src 'self' 'unsafe-inline'; "
+                    "img-src 'self' data: https:; "
+                    "font-src 'self' data:; "
+                    "connect-src 'self'; "
+                    "frame-ancestors 'none'; "
+                    "base-uri 'self'; "
+                    "form-action 'self';"
+                )
+
+        return response

tasks/models.py

@@ -136,9 +136,18 @@ class Task(models.Model):
         db_table = 'tasks'
         ordering = ['sort_order', '-priority', 'due_date', 'created_at']
 
+    # Fields that affect when/whether reminder notifications should fire.
+    REMINDER_TRACKED_FIELDS = ('due_date', 'due_time', 'reminder_at', 'status', 'is_deleted')
+
     def __str__(self):
         return self.title
 
+    @classmethod
+    def from_db(cls, db, field_names, values):
+        instance = super().from_db(db, field_names, values)
+        instance._loaded_values = dict(zip(field_names, values))
+        return instance
+
     def save(self, *args, **kwargs):
         # Auto-set completed_at when status changes to completed
         if self.status == 'completed' and self.completed_at is None:
@@ -146,14 +155,104 @@ class Task(models.Model):
             self.completed_at = timezone.now()
         elif self.status != 'completed':
             self.completed_at = None
+
+        is_new = self._state.adding
+        loaded_values = getattr(self, '_loaded_values', None)
+        reminder_fields_changed = is_new or loaded_values is None or any(
+            loaded_values.get(field) != getattr(self, field) for field in self.REMINDER_TRACKED_FIELDS
+        )
+
         super().save(*args, **kwargs)
+        self._loaded_values = {field: getattr(self, field) for field in self.REMINDER_TRACKED_FIELDS}
+
+        if reminder_fields_changed:
+            self.reschedule_reminders()
+
+    def _due_and_overdue_moments(self):
+        """
+        Returns (due_moment, overdue_moment) as timezone-aware datetimes in
+        the owner's timezone, or (None, None) if there's nothing to schedule
+        against. Mirrors is_overdue's rule that a date-only due task doesn't
+        flip overdue until the day after due_date.
+        """
+        if not self.due_date:
+            return None, None
+
+        from datetime import datetime, time as dt_time, timedelta
+        from zoneinfo import ZoneInfo
+
+        try:
+            user_tz = ZoneInfo(self.user.timezone)
+        except Exception:
+            user_tz = ZoneInfo('UTC')
+
+        if self.due_time:
+            due_moment = datetime.combine(self.due_date, self.due_time, tzinfo=user_tz)
+            # Give "overdue" some breathing room after "due now" instead of
+            # firing both notifications at the exact same moment.
+            return due_moment, due_moment + timedelta(hours=1)
+
+        overdue_moment = datetime.combine(self.due_date + timedelta(days=1), dt_time.min, tzinfo=user_tz)
+        return None, overdue_moment
+
+    def reschedule_reminders(self):
+        """
+        Recompute this task's ScheduledReminder rows from its current
+        due_date/due_time/reminder_at/status. Safe to call any time due
+        info changes - clears out not-yet-sent reminders and, if the task
+        is still active and due, schedules fresh ones for "before due"
+        (from reminder_at, or user.default_reminder_minutes before due),
+        "due now", and "overdue".
+        """
+        from datetime import timedelta
+        from notifications.models import ScheduledReminder
+
+        ScheduledReminder.objects.filter(task=self, is_sent=False).delete()
+
+        if self.is_deleted or self.status in ('completed', 'cancelled'):
+            return
+
+        due_moment, overdue_moment = self._due_and_overdue_moments()
+        reminders = []
+
+        if due_moment:
+            if self.reminder_at:
+                before_due_moment = self.reminder_at
+            elif self.user.default_reminder_minutes:
+                before_due_moment = due_moment - timedelta(minutes=self.user.default_reminder_minutes)
+            else:
+                before_due_moment = None
+
+            if before_due_moment:
+                reminders.append(ScheduledReminder(task=self, reminder_type='reminder', remind_at=before_due_moment))
+            reminders.append(ScheduledReminder(task=self, reminder_type='due_soon', remind_at=due_moment))
+
+        if overdue_moment:
+            reminders.append(ScheduledReminder(task=self, reminder_type='overdue', remind_at=overdue_moment))
+
+        if reminders:
+            ScheduledReminder.objects.bulk_create(reminders)
 
     @property
     def is_overdue(self):
         """Check if task is overdue."""
         if self.due_date and self.status not in ('completed', 'cancelled'):
             from django.utils import timezone
-            return self.due_date < timezone.now().date()
+            from zoneinfo import ZoneInfo
+
+            # Get current date/time in user's timezone
+            try:
+                user_tz = ZoneInfo(self.user.timezone)
+                user_now = timezone.now().astimezone(user_tz)
+            except (Exception,):
+                # Fall back to UTC if user timezone is invalid or missing
+                user_now = timezone.now()
+
+            if self.due_date < user_now.date():
+                return True
+            if self.due_date == user_now.date() and self.due_time:
+                return self.due_time < user_now.time()
+            return False
         return False
 
     @property
@@ -174,6 +273,146 @@ class Task(models.Model):
         secs = seconds % 60
         return f"{hours}:{minutes:02d}:{secs:02d}"
 
+    def calculate_next_due_date(self, from_date=None):
+        """
+        Calculate the next due date based on recurrence pattern.
+        Returns None if task doesn't recur or has reached end date.
+        """
+        if self.recurrence == 'none':
+            return None
+
+        from datetime import timedelta
+        from dateutil.relativedelta import relativedelta
+
+        base_date = from_date or self.due_date
+        if not base_date:
+            from django.utils import timezone
+            base_date = timezone.now().date()
+
+        # Calculate next date based on recurrence type
+        if self.recurrence == 'daily':
+            next_date = base_date + timedelta(days=1)
+        elif self.recurrence == 'weekly':
+            next_date = base_date + timedelta(weeks=1)
+        elif self.recurrence == 'biweekly':
+            next_date = base_date + timedelta(weeks=2)
+        elif self.recurrence == 'monthly':
+            next_date = base_date + relativedelta(months=1)
+        elif self.recurrence == 'yearly':
+            next_date = base_date + relativedelta(years=1)
+        elif self.recurrence == 'custom' and self.recurrence_rule:
+            from dateutil.rrule import rrulestr
+            from datetime import datetime, time as dt_time
+
+            dtstart = datetime.combine(base_date, dt_time.min)
+            try:
+                next_occurrence = rrulestr(self.recurrence_rule, dtstart=dtstart).after(dtstart, inc=False)
+            except Exception:
+                return None
+            if not next_occurrence:
+                return None
+            next_date = next_occurrence.date()
+        else:
+            return None
+
+        # Check if we've passed the end date
+        if self.recurrence_end_date and next_date > self.recurrence_end_date:
+            return None
+
+        return next_date
+
+    @property
+    def parsed_custom_recurrence(self):
+        """
+        Decompose recurrence_rule (an RRULE string) into simple fields for
+        prepopulating the custom recurrence builder UI. Never raises; returns
+        safe defaults for a blank or malformed rule.
+        """
+        result = {
+            'freq': None,
+            'interval': 1,
+            'byweekday': [],
+            'monthly_mode': None,
+            'bymonthday': None,
+            'nth_ordinal': None,
+            'nth_weekday': None,
+        }
+        if not self.recurrence_rule:
+            return result
+
+        import re
+
+        params = {}
+        for part in self.recurrence_rule.split(';'):
+            if '=' in part:
+                key, value = part.split('=', 1)
+                params[key.strip().upper()] = value.strip()
+
+        freq = params.get('FREQ', '').upper()
+        if freq not in ('WEEKLY', 'MONTHLY'):
+            return result
+        result['freq'] = freq.lower()
+
+        try:
+            result['interval'] = int(params.get('INTERVAL', '1'))
+        except ValueError:
+            result['interval'] = 1
+
+        byday = params.get('BYDAY', '')
+
+        if freq == 'WEEKLY':
+            if byday:
+                result['byweekday'] = [d.strip() for d in byday.split(',') if d.strip()]
+        elif freq == 'MONTHLY':
+            bymonthday = params.get('BYMONTHDAY')
+            if bymonthday:
+                try:
+                    result['bymonthday'] = int(bymonthday)
+                    result['monthly_mode'] = 'day'
+                except ValueError:
+                    pass
+            elif byday:
+                match = re.match(r'^(-?\d+)([A-Z]{2})$', byday)
+                if match:
+                    result['nth_ordinal'] = int(match.group(1))
+                    result['nth_weekday'] = match.group(2)
+                    result['monthly_mode'] = 'nth'
+
+        return result
+
+    def create_next_recurrence(self):
+        """
+        Create the next instance of this recurring task.
+        Returns the new task or None if no recurrence should be created.
+        """
+        if self.recurrence == 'none':
+            return None
+
+        next_due_date = self.calculate_next_due_date()
+        if not next_due_date:
+            return None
+
+        # Create new task with same properties
+        new_task = Task.objects.create(
+            user=self.user,
+            parent=self.parent,
+            title=self.title,
+            description=self.description,
+            status='pending',
+            priority=self.priority,
+            due_date=next_due_date,
+            due_time=self.due_time,
+            recurrence=self.recurrence,
+            recurrence_rule=self.recurrence_rule,
+            recurrence_end_date=self.recurrence_end_date,
+            sort_order=self.sort_order,
+        )
+
+        # Copy tags
+        new_task.tags.set(self.tags.all())
+
+        return new_task
+
 
 class TimeEntry(models.Model):
     """

tasks/tests.py

@@ -1,3 +1,179 @@
-from django.test import TestCase
+from datetime import date, datetime, time as dt_time
+from unittest.mock import patch
 
-# Create your tests here.
+from django.contrib.auth import get_user_model
+from django.test import TestCase
+from django.utils import timezone as django_timezone
+
+from tasks.models import Task
+
+User = get_user_model()
+
+
+class CustomRecurrenceTests(TestCase):
+    """Tests for Task.calculate_next_due_date() with custom RRULE patterns."""
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='testuser',
+            email='testuser@example.com',
+            password='testpass123',
+        )
+
+    def make_task(self, **kwargs):
+        defaults = {
+            'user': self.user,
+            'title': 'Test task',
+            'recurrence': 'custom',
+        }
+        defaults.update(kwargs)
+        return Task.objects.create(**defaults)
+
+    def test_every_wednesday(self):
+        # 2026-01-07 is a Wednesday
+        task = self.make_task(due_date=date(2026, 1, 7), recurrence_rule='FREQ=WEEKLY;BYDAY=WE')
+        self.assertEqual(task.calculate_next_due_date(), date(2026, 1, 14))
+
+    def test_every_other_wednesday(self):
+        task = self.make_task(due_date=date(2026, 1, 7), recurrence_rule='FREQ=WEEKLY;INTERVAL=2;BYDAY=WE')
+        self.assertEqual(task.calculate_next_due_date(), date(2026, 1, 21))
+
+    def test_every_second_tuesday(self):
+        # 2026-01-13 is the second Tuesday of January 2026
+        task = self.make_task(due_date=date(2026, 1, 13), recurrence_rule='FREQ=MONTHLY;BYDAY=2TU')
+        self.assertEqual(task.calculate_next_due_date(), date(2026, 2, 10))
+
+    def test_every_15th(self):
+        task = self.make_task(due_date=date(2026, 1, 15), recurrence_rule='FREQ=MONTHLY;BYMONTHDAY=15')
+        self.assertEqual(task.calculate_next_due_date(), date(2026, 2, 15))
+
+    def test_respects_recurrence_end_date(self):
+        task = self.make_task(
+            due_date=date(2026, 1, 7),
+            recurrence_rule='FREQ=WEEKLY;BYDAY=WE',
+            recurrence_end_date=date(2026, 1, 10),
+        )
+        self.assertIsNone(task.calculate_next_due_date())
+
+    def test_malformed_rule_returns_none(self):
+        task = self.make_task(due_date=date(2026, 1, 7), recurrence_rule='not a valid rrule')
+        self.assertIsNone(task.calculate_next_due_date())
+
+    def test_create_next_recurrence(self):
+        task = self.make_task(due_date=date(2026, 1, 15), recurrence_rule='FREQ=MONTHLY;BYMONTHDAY=15')
+        new_task = task.create_next_recurrence()
+        self.assertIsNotNone(new_task)
+        self.assertEqual(new_task.due_date, date(2026, 2, 15))
+        self.assertEqual(new_task.recurrence_rule, 'FREQ=MONTHLY;BYMONTHDAY=15')
+        self.assertEqual(new_task.status, 'pending')
+
+    def test_parsed_custom_recurrence_weekly(self):
+        task = self.make_task(recurrence_rule='FREQ=WEEKLY;INTERVAL=2;BYDAY=WE')
+        parsed = task.parsed_custom_recurrence
+        self.assertEqual(parsed['freq'], 'weekly')
+        self.assertEqual(parsed['interval'], 2)
+        self.assertEqual(parsed['byweekday'], ['WE'])
+
+    def test_parsed_custom_recurrence_monthly_nth(self):
+        task = self.make_task(recurrence_rule='FREQ=MONTHLY;BYDAY=2TU')
+        parsed = task.parsed_custom_recurrence
+        self.assertEqual(parsed['freq'], 'monthly')
+        self.assertEqual(parsed['monthly_mode'], 'nth')
+        self.assertEqual(parsed['nth_ordinal'], 2)
+        self.assertEqual(parsed['nth_weekday'], 'TU')
+
+    def test_parsed_custom_recurrence_blank(self):
+        task = self.make_task(recurrence_rule='')
+        parsed = task.parsed_custom_recurrence
+        self.assertIsNone(parsed['freq'])
+        self.assertEqual(parsed['byweekday'], [])
+
+
+class IsOverdueTests(TestCase):
+    """Tests for Task.is_overdue, which must account for due_time, not just due_date (Gitea #7)."""
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='overdueuser',
+            email='overdueuser@example.com',
+            password='testpass123',
+        )
+
+    def make_task(self, **kwargs):
+        defaults = {'user': self.user, 'title': 'Test task', 'status': 'pending'}
+        defaults.update(kwargs)
+        return Task.objects.create(**defaults)
+
+    @patch('django.utils.timezone.now')
+    def test_not_overdue_before_due_time_same_day(self, mock_now):
+        mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 15, 8, 0, 0))
+        task = self.make_task(due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0))
+        self.assertFalse(task.is_overdue)
+
+    @patch('django.utils.timezone.now')
+    def test_overdue_after_due_time_same_day(self, mock_now):
+        mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 15, 18, 0, 0))
+        task = self.make_task(due_date=date(2026, 1, 15), due_time=dt_time(17, 0, 0))
+        self.assertTrue(task.is_overdue)
+
+    @patch('django.utils.timezone.now')
+    def test_not_overdue_same_day_without_due_time(self, mock_now):
+        mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 15, 23, 59, 0))
+        task = self.make_task(due_date=date(2026, 1, 15), due_time=None)
+        self.assertFalse(task.is_overdue)
+
+    @patch('django.utils.timezone.now')
+    def test_overdue_once_date_has_passed(self, mock_now):
+        mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 16, 0, 1, 0))
+        task = self.make_task(due_date=date(2026, 1, 15), due_time=dt_time(23, 0, 0))
+        self.assertTrue(task.is_overdue)
+
+    @patch('django.utils.timezone.now')
+    def test_completed_task_never_overdue(self, mock_now):
+        mock_now.return_value = django_timezone.make_aware(datetime(2026, 1, 15, 23, 0, 0))
+        task = self.make_task(due_date=date(2026, 1, 1), due_time=dt_time(9, 0, 0), status='completed')
+        self.assertFalse(task.is_overdue)
+
+
+class WebFormDueDateTypeTests(TestCase):
+    """
+    The web views assign due_date/due_time straight from request.POST (raw
+    strings), relying on Django to coerce them at the DB layer - which
+    leaves the in-memory instance holding strings after save(). Anything
+    that touches those fields on that same instance afterward (e.g.
+    Task.reschedule_reminders(), called from save() itself) must not choke
+    on that. Regression test for a real production crash on task edit.
+    """
+
+    def setUp(self):
+        self.user = User.objects.create_user(
+            username='webformuser', email='webformuser@example.com', password='testpass123',
+        )
+        self.client.force_login(self.user)
+
+    def test_editing_due_date_and_time_does_not_crash(self):
+        task = Task.objects.create(user=self.user, title='Task')
+        response = self.client.post(f'/tasks/{task.id}/', {
+            'title': 'Task', 'status': 'pending', 'priority': 'medium',
+            'due_date': '2026-09-10', 'due_time': '17:00', 'recurrence': 'none',
+        })
+        self.assertEqual(response.status_code, 302)
+        task.refresh_from_db()
+        self.assertEqual(task.due_date, date(2026, 9, 10))
+        self.assertEqual(task.due_time, dt_time(17, 0))
+
+    def test_creating_task_with_due_date_does_not_crash(self):
+        response = self.client.post('/tasks/new/', {
+            'title': 'New task', 'status': 'pending', 'priority': 'medium',
+            'due_date': '2026-09-10', 'due_time': '17:00', 'recurrence': 'none',
+        })
+        self.assertEqual(response.status_code, 302)
+        task = Task.objects.get(title='New task')
+        self.assertEqual(task.due_date, date(2026, 9, 10))
+        self.assertEqual(task.due_time, dt_time(17, 0))
+
+    def test_quick_add_task_with_due_date_does_not_crash(self):
+        response = self.client.post('/tasks/quick-add/', {'title': 'Quick task', 'due_date': '2026-09-10'})
+        self.assertEqual(response.status_code, 302)
+        task = Task.objects.get(title='Quick task')
+        self.assertEqual(task.due_date, date(2026, 9, 10))

tasks/views.py

@@ -7,6 +7,7 @@ from django.contrib.auth.decorators import login_required
 from django.db.models import Q
 from django.shortcuts import render, redirect, get_object_or_404
 from django.utils import timezone
+from django.utils.dateparse import parse_date, parse_time
 from django.utils.http import url_has_allowed_host_and_scheme
 from django.views import View
 from django.views.decorators.http import require_POST
@@ -218,13 +219,21 @@ class DashboardView(View):
         if not request.user.is_authenticated:
             return redirect('login')
 
-        today = timezone.now().date()
+        # Get today's date in user's timezone
+        from zoneinfo import ZoneInfo
+        try:
+            user_tz = ZoneInfo(request.user.timezone)
+            user_now = timezone.now().astimezone(user_tz)
+            today = user_now.date()
+        except (Exception,):
+            # Fall back to UTC if user timezone is invalid or missing
+            today = timezone.now().date()
 
         # Get filter parameters
         current_filter = request.GET.get('filter', 'all')
         current_tag_id = request.GET.get('tag')
         selected_task_id = request.GET.get('selected')
-        current_sort = request.GET.get('sort', 'default')
+        current_sort = request.GET.get('sort', 'due_date')
 
         # Base query
         tasks = Task.objects.filter(
@@ -271,20 +280,37 @@ class DashboardView(View):
 
         # Apply sorting before converting to list
         if not isinstance(tasks, list):
+            # Define priority order for sorting
+            from django.db.models import Case, When, IntegerField, F
+            priority_order_case = Case(
+                When(priority='urgent', then=4),
+                When(priority='high', then=3),
+                When(priority='medium', then=2),
+                When(priority='low', then=1),
+                default=0,
+                output_field=IntegerField(),
+            )
+
             if current_sort == 'due_date':
                 # Sort by due date (nulls last), then priority
-                from django.db.models import F
-                tasks = tasks.order_by(F('due_date').asc(nulls_last=True), '-priority')
+                tasks = tasks.annotate(priority_order=priority_order_case).order_by(
+                    F('due_date').asc(nulls_last=True), '-priority_order'
+                )
             elif current_sort == 'due_date_desc':
                 # Sort by due date descending (nulls last), then priority
-                from django.db.models import F
-                tasks = tasks.order_by(F('due_date').desc(nulls_last=True), '-priority')
+                tasks = tasks.annotate(priority_order=priority_order_case).order_by(
+                    F('due_date').desc(nulls_last=True), '-priority_order'
+                )
             elif current_sort == 'priority':
-                # Sort by priority, then due date
-                tasks = tasks.order_by('-priority', 'due_date')
+                # Sort by priority (high to low), then due date
+                tasks = tasks.annotate(priority_order=priority_order_case).order_by(
+                    '-priority_order', 'due_date'
+                )
             elif current_sort == 'priority_low':
                 # Sort by priority (low to high), then due date
-                tasks = tasks.order_by('priority', 'due_date')
+                tasks = tasks.annotate(priority_order=priority_order_case).order_by(
+                    'priority_order', 'due_date'
+                )
             # else: default ordering from model (sort_order, -priority, due_date, created_at)
 
         # Convert to list if not already (for overdue filter)
@@ -293,7 +319,7 @@ class DashboardView(View):
 
         # Apply sorting to lists (for overdue filter case)
         else:
-            priority_order = {'high': 3, 'medium': 2, 'low': 1}
+            priority_order = {'urgent': 4, 'high': 3, 'medium': 2, 'low': 1}
             if current_sort == 'due_date':
                 tasks = sorted(tasks, key=lambda t: (t.due_date or timezone.now().date() + timezone.timedelta(days=9999), -priority_order.get(t.priority, 0)))
             elif current_sort == 'due_date_desc':
@@ -425,6 +451,9 @@ class TaskDetailView(View):
         task.title = request.POST.get('title', task.title)
         task.description = request.POST.get('description', '')
 
+        # Track old status to detect completion
+        old_status = task.status
+
         # Validate status against allowed choices
         status = request.POST.get('status', task.status)
         valid_statuses = [choice[0] for choice in Task.STATUS_CHOICES]
@@ -438,10 +467,10 @@ class TaskDetailView(View):
             task.priority = priority
 
         due_date = request.POST.get('due_date')
-        task.due_date = due_date if due_date else None
+        task.due_date = parse_date(due_date) if due_date else None
 
         due_time = request.POST.get('due_time')
-        task.due_time = due_time if due_time else None
+        task.due_time = parse_time(due_time) if due_time else None
 
         # Validate recurrence against allowed choices
         recurrence = request.POST.get('recurrence', 'none')
@@ -451,6 +480,12 @@ class TaskDetailView(View):
         else:
             task.recurrence = 'none'
 
+        task.recurrence_rule = request.POST.get('recurrence_rule', '') if task.recurrence == 'custom' else ''
+
+        # Create next recurrence if task is being marked as completed
+        if old_status != 'completed' and task.status == 'completed' and task.recurrence != 'none':
+            task.create_next_recurrence()
+
         task.save()
 
         # Handle tags
@@ -506,9 +541,10 @@ class TaskCreateView(View):
             description=request.POST.get('description', ''),
             status=status,
             priority=priority,
-            due_date=request.POST.get('due_date') or None,
-            due_time=request.POST.get('due_time') or None,
+            due_date=parse_date(request.POST.get('due_date')) if request.POST.get('due_date') else None,
+            due_time=parse_time(request.POST.get('due_time')) if request.POST.get('due_time') else None,
             recurrence=recurrence,
+            recurrence_rule=request.POST.get('recurrence_rule', '') if recurrence == 'custom' else '',
         )
 
         tag_ids = request.POST.getlist('tags')
@@ -524,7 +560,7 @@ def task_quick_add(request):
     task = Task.objects.create(
         user=request.user,
         title=request.POST.get('title'),
-        due_date=request.POST.get('due_date') or None,
+        due_date=parse_date(request.POST.get('due_date')) if request.POST.get('due_date') else None,
     )
     # Handle optional tag
     tag_id = request.POST.get('tag')
@@ -564,7 +600,13 @@ def task_toggle_status(request, task_id):
     if task.status == 'completed':
         task.status = 'pending'
     else:
+        # Mark as completed
         task.status = 'completed'
+
+        # Create next recurrence if this is a recurring task
+        if task.recurrence != 'none':
+            task.create_next_recurrence()
+
     task.save()
 
     next_url = request.POST.get('next', 'dashboard')

tasks/views_debug.py

@@ -0,0 +1,40 @@
+"""Debug views for troubleshooting mobile app."""
+
+from django.http import JsonResponse, HttpResponse
+from django.views.decorators.csrf import csrf_exempt
+from django.views.decorators.http import require_http_methods
+
+
+@csrf_exempt
+@require_http_methods(["GET", "POST"])
+def debug_user_agent(request):
+    """Return the User-Agent header for debugging mobile app."""
+    user_agent = request.META.get('HTTP_USER_AGENT', 'No User-Agent')
+
+    # Simple HTML response that's easy to see in iframe
+    html = f"""
+    <!DOCTYPE html>
+    <html>
+    <head>
+        <title>Debug Info</title>
+        <style>
+            body {{ font-family: monospace; padding: 20px; }}
+            .detected {{ color: green; font-weight: bold; }}
+            .not-detected {{ color: red; font-weight: bold; }}
+        </style>
+    </head>
+    <body>
+        <h2>Mobile App Debug Info</h2>
+        <p><strong>User-Agent:</strong><br>{user_agent}</p>
+        <p><strong>Contains 'wv':</strong> {'wv' in user_agent.lower()}</p>
+        <p><strong>Contains 'CapacitorHttp':</strong> {'CapacitorHttp' in user_agent}</p>
+        <p><strong>Is Mobile App Detected:</strong>
+        <span class="{'detected' if ('wv' in user_agent.lower() or 'CapacitorHttp' in user_agent) else 'not-detected'}">
+        {('wv' in user_agent.lower() or 'CapacitorHttp' in user_agent)}
+        </span>
+        </p>
+    </body>
+    </html>
+    """
+
+    return HttpResponse(html)

templates/base.html

@@ -9,8 +9,15 @@
     <!-- Favicon -->
     <link rel="icon" type="image/svg+xml" href="{% static 'favicons/favicon.svg' %}">
     <link rel="alternate icon" href="{% static 'favicons/favicon.svg' %}" type="image/svg+xml">
+    <link rel="apple-touch-icon" href="{% static 'favicons/apple-touch-icon-180.png' %}">
 
-    <link rel="stylesheet" href="{% static 'css/app.css' %}">
+    <!-- PWA -->
+    <link rel="manifest" href="{% url 'manifest' %}">
+    <meta name="theme-color" content="#3B82F6">
+    <meta name="mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-capable" content="yes">
+
+    <link rel="stylesheet" href="{% static 'css/app.css' %}?v=6">
     {% block extra_css %}{% endblock %}
 </head>
 <body>
@@ -140,7 +147,9 @@
     {% endif %}
     {% endblock %}
 
-    <script src="{% static 'js/app.js' %}?v=3"></script>
+    <script src="{% static 'js/offline-db.js' %}?v=7"></script>
+    <script src="{% static 'js/offline-sync.js' %}?v=10"></script>
+    <script src="{% static 'js/app.js' %}?v=9"></script>
     {% block extra_js %}{% endblock %}
 </body>
 </html>

templates/manifest.webmanifest

@@ -0,0 +1,26 @@
+{% load static %}{
+    "name": "KeepItGoing",
+    "short_name": "KeepItGoing",
+    "start_url": "/",
+    "display": "standalone",
+    "background_color": "#ffffff",
+    "theme_color": "#3B82F6",
+    "icons": [
+        {
+            "src": "{% static 'favicons/icon-192.png' %}",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "{% static 'favicons/icon-512.png' %}",
+            "sizes": "512x512",
+            "type": "image/png"
+        },
+        {
+            "src": "{% static 'favicons/icon-512-maskable.png' %}",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "maskable"
+        }
+    ]
+}

templates/offline.html

@@ -0,0 +1,19 @@
+{% extends 'base.html' %}
+
+{% block title %}You're Offline - KeepItGoing{% endblock %}
+
+{% block content %}
+<div class="empty-state">
+    <p>You're offline</p>
+    <p class="text-muted">This page isn't available without a connection. Reconnect and try again.</p>
+    <button class="btn btn-primary" onclick="window.location.reload()">Retry</button>
+</div>
+{% endblock %}
+
+{% block auth_content %}
+<div class="empty-state">
+    <p>You're offline</p>
+    <p class="text-muted">This page isn't available without a connection. Reconnect and try again.</p>
+    <button class="btn btn-primary" onclick="window.location.reload()">Retry</button>
+</div>
+{% endblock %}

templates/offline_tasks.html

@@ -0,0 +1,166 @@
+{% load static %}<!DOCTYPE html>
+<html lang="en" data-theme="light">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Offline - KeepItGoing</title>
+    <link rel="icon" type="image/svg+xml" href="{% static 'favicons/favicon.svg' %}">
+    <link rel="stylesheet" href="{% static 'css/app.css' %}">
+    <script>
+        (function() {
+            var saved = localStorage.getItem('theme');
+            var systemDark = window.matchMedia('(prefers-color-scheme: dark)').matches;
+            if (saved === 'dark' || (!saved && systemDark)) {
+                document.documentElement.setAttribute('data-theme', 'dark');
+            }
+        })();
+    </script>
+</head>
+<body>
+    <div class="app-layout detail-closed" id="app">
+        <!-- Header (offline-tinted so it's unmistakable which mode you're in) -->
+        <header class="app-header" style="background-color: #d97706; color: #fff; border-bottom-color: #b45309;">
+            <div style="display: flex; align-items: center; gap: var(--space-md);">
+                <button class="sidebar-toggle" onclick="toggleOfflineSidebar()" aria-label="Toggle sidebar" style="color: #fff;">
+                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                        <path d="M3 12h18M3 6h18M3 18h18"/>
+                    </svg>
+                </button>
+                <span class="app-brand" style="color: #fff;">KeepItGoing</span>
+                <span style="font-size: var(--font-sm); font-weight: 600;">⚠ Offline — changes sync automatically once you're back online</span>
+            </div>
+            <div class="app-header-actions">
+                <button class="theme-toggle" onclick="toggleOfflineTheme()" aria-label="Toggle theme" title="Toggle dark/light mode" style="color: #fff;">
+                    <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                        <circle cx="12" cy="12" r="5"/>
+                        <path d="M12 1v2M12 21v2M4.22 4.22l1.42 1.42M18.36 18.36l1.42 1.42M1 12h2M21 12h2M4.22 19.78l1.42-1.42M18.36 5.64l1.42-1.42"/>
+                    </svg>
+                </button>
+            </div>
+        </header>
+
+        <!-- Sidebar -->
+        <aside class="app-sidebar" id="sidebar">
+            <div class="sidebar-section">
+                <div class="sidebar-section-title">Filters</div>
+                <nav class="sidebar-nav" id="offline-filter-nav">
+                    <a href="#" class="sidebar-item active" data-filter="all">
+                        <svg class="sidebar-item-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <path d="M3 12h18M3 6h18M3 18h18"/>
+                        </svg>
+                        All Tasks
+                    </a>
+                    <a href="#" class="sidebar-item" data-filter="today">
+                        <svg class="sidebar-item-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <circle cx="12" cy="12" r="10"/>
+                            <path d="M12 6v6l4 2"/>
+                        </svg>
+                        Today
+                    </a>
+                    <a href="#" class="sidebar-item" data-filter="upcoming">
+                        <svg class="sidebar-item-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <rect x="3" y="4" width="18" height="18" rx="2" ry="2"/>
+                            <path d="M16 2v4M8 2v4M3 10h18"/>
+                        </svg>
+                        Upcoming
+                    </a>
+                    <a href="#" class="sidebar-item" data-filter="overdue">
+                        <svg class="sidebar-item-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <circle cx="12" cy="12" r="10"/>
+                            <path d="M12 8v4M12 16h.01"/>
+                        </svg>
+                        Overdue
+                    </a>
+                    <a href="#" class="sidebar-item" data-filter="completed">
+                        <svg class="sidebar-item-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                            <path d="M22 11.08V12a10 10 0 1 1-5.93-9.14"/>
+                            <path d="M22 4L12 14.01l-3-3"/>
+                        </svg>
+                        Completed
+                    </a>
+                </nav>
+            </div>
+
+            <div class="sidebar-section">
+                <div class="sidebar-section-title">Tags</div>
+                <nav class="sidebar-nav" id="offline-tag-nav"></nav>
+                <button type="button" class="sidebar-add-btn" id="offline-add-tag-btn">
+                    <svg style="width: 14px; height: 14px;" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                        <path d="M12 5v14M5 12h14"/>
+                    </svg>
+                    Add Tag
+                </button>
+            </div>
+        </aside>
+
+        <!-- Main Task Pane -->
+        <main class="task-pane">
+            <div class="task-pane-header">
+                <h1 class="task-pane-title" id="offline-page-title">All Tasks</h1>
+                <select id="offline-sort-select" class="form-select" style="width: auto;">
+                    <option value="due_date">Due Date (Earliest)</option>
+                    <option value="due_date_desc">Due Date (Latest)</option>
+                    <option value="priority">Priority (High to Low)</option>
+                    <option value="priority_low">Priority (Low to High)</option>
+                </select>
+            </div>
+
+            <form id="offline-add-task-form" class="quick-add">
+                <input type="text" id="offline-task-title" class="quick-add-input" placeholder="Add a new task..." required>
+                <button type="submit" class="btn btn-primary">Add</button>
+            </form>
+
+            <div id="offline-empty-state" class="empty-state" hidden>
+                <p>Loading...</p>
+            </div>
+            <div class="task-list" id="offline-task-list"></div>
+        </main>
+
+        <!-- Detail Panel -->
+        <aside class="detail-pane hidden" id="detail-pane">
+            <div class="empty-state">
+                <p>Select a task to view details</p>
+            </div>
+        </aside>
+
+        <!-- Mobile overlay -->
+        <div class="mobile-overlay" id="mobile-overlay" onclick="closeOfflineMobileMenus()"></div>
+    </div>
+
+    <!-- Tag Edit/Create Modal (outside app-layout for proper fixed positioning) -->
+    <div class="modal-backdrop" id="tag-modal-backdrop">
+        <div class="modal" onclick="event.stopPropagation()">
+            <div class="modal-header">
+                <h2 class="modal-title" id="tag-modal-title">New Tag</h2>
+                <button type="button" class="modal-close" id="tag-modal-close-btn">
+                    <svg style="width: 20px; height: 20px;" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                        <path d="M18 6L6 18M6 6l12 12"/>
+                    </svg>
+                </button>
+            </div>
+            <form id="tag-edit-form">
+                <div class="form-group">
+                    <label class="form-label" for="tag-modal-name">Name</label>
+                    <input type="text" class="form-input" id="tag-modal-name" required placeholder="Tag name">
+                </div>
+                <div class="form-group">
+                    <label class="form-label">Color</label>
+                    <div class="color-presets" id="tag-modal-color-presets"></div>
+                    <div class="color-custom-row">
+                        <label class="color-custom-label">Custom:</label>
+                        <input type="color" id="tag-modal-color" class="color-custom-input" value="#3b82f6">
+                    </div>
+                </div>
+                <div class="modal-actions">
+                    <button type="button" class="btn btn-secondary" id="tag-modal-cancel-btn">Cancel</button>
+                    <button type="button" class="btn btn-danger" id="tag-modal-delete-btn" style="display: none;">Delete</button>
+                    <button type="submit" class="btn btn-primary" id="tag-modal-submit-btn">Create</button>
+                </div>
+            </form>
+        </div>
+    </div>
+
+    <script src="{% static 'js/offline-db.js' %}"></script>
+    <script src="{% static 'js/offline-tasks.js' %}"></script>
+</body>
+</html>

templates/sw.js

@@ -0,0 +1,96 @@
+{% load static %}const CACHE_NAME = 'keepitgoing-shell-v10';
+const OFFLINE_URL = '{% url "offline" %}';
+const OFFLINE_TASKS_URL = '{% url "offline-tasks" %}';
+
+const PRECACHE_URLS = [
+    "{% static 'css/app.css' %}",
+    "{% static 'js/app.js' %}",
+    "{% static 'js/offline-db.js' %}",
+    "{% static 'js/offline-tasks.js' %}",
+    "{% static 'favicons/favicon.svg' %}",
+    "{% static 'favicons/icon-192.png' %}",
+    "{% static 'favicons/icon-512.png' %}",
+    "{% static 'favicons/icon-512-maskable.png' %}",
+    "{% static 'favicons/apple-touch-icon-180.png' %}",
+    OFFLINE_URL,
+    OFFLINE_TASKS_URL,
+];
+
+self.addEventListener('install', (event) => {
+    event.waitUntil(
+        caches.open(CACHE_NAME).then((cache) =>
+            // cache.addAll() lets the browser's own HTTP cache satisfy each
+            // fetch - static assets here have no Cache-Control/ETag (only
+            // Last-Modified), so a heuristically-cached stale response can
+            // silently win even on a CACHE_NAME bump. { cache: 'reload' }
+            // forces a real network round-trip so precache always reflects
+            // what the server currently serves.
+            Promise.all(
+                PRECACHE_URLS.map((url) =>
+                    fetch(url, { cache: 'reload' }).then((response) => cache.put(url, response))
+                )
+            )
+        )
+    );
+    self.skipWaiting();
+});
+
+self.addEventListener('activate', (event) => {
+    event.waitUntil(
+        caches.keys().then((keys) =>
+            Promise.all(keys.filter((key) => key !== CACHE_NAME).map((key) => caches.delete(key)))
+        )
+    );
+    self.clients.claim();
+});
+
+self.addEventListener('fetch', (event) => {
+    const request = event.request;
+
+    // Navigations: try the network first, fall back to the offline page.
+    // The dashboard route falls back to the offline-capable task app instead
+    // of the generic offline page, since it can still show/edit cached tasks.
+    // A 5xx response (e.g. a reverse proxy up-front returning 502/503 while
+    // the app server itself is down) is treated the same as a network
+    // failure - fetch() only rejects on true network errors, not bad status
+    // codes, so that has to be checked explicitly.
+    if (request.mode === 'navigate') {
+        event.respondWith(
+            fetch(request).then((response) => {
+                if (response.status >= 500) {
+                    throw new Error(`Server error: ${response.status}`);
+                }
+                return response;
+            }).catch(() => {
+                const path = new URL(request.url).pathname;
+                return caches.match(path === '/' ? OFFLINE_TASKS_URL : OFFLINE_URL);
+            })
+        );
+        return;
+    }
+
+    // Precached shell assets: serve from cache first.
+    const path = new URL(request.url).pathname;
+    if (PRECACHE_URLS.includes(path)) {
+        event.respondWith(
+            caches.match(request).then((cached) => cached || fetch(request))
+        );
+    }
+});
+
+self.addEventListener('push', (event) => {
+    const data = event.data ? event.data.json() : {};
+    event.waitUntil(
+        self.registration.showNotification(data.title || 'KeepItGoing', {
+            body: data.body || '',
+            icon: '{% static "favicons/icon-192.png" %}',
+            badge: '{% static "favicons/icon-192.png" %}',
+            data: { url: data.url || '/' },
+        })
+    );
+});
+
+self.addEventListener('notificationclick', (event) => {
+    event.notification.close();
+    event.waitUntil(clients.openWindow(event.notification.data.url || '/'));
+});

templates/tasks/_recurrence_fields.html

@@ -0,0 +1,102 @@
+<!-- Recurrence -->
+{% with parsed=task.parsed_custom_recurrence %}
+<div class="form-group">
+    <label class="form-label" for="{{ id_prefix }}recurrence">Recurrence</label>
+    <select class="form-select" id="{{ id_prefix }}recurrence" name="recurrence" onchange="toggleCustomRecurrenceBuilder(this)">
+        <option value="none" {% if not task or task.recurrence == 'none' %}selected{% endif %}>None</option>
+        <option value="daily" {% if task.recurrence == 'daily' %}selected{% endif %}>Daily</option>
+        <option value="weekly" {% if task.recurrence == 'weekly' %}selected{% endif %}>Weekly</option>
+        <option value="biweekly" {% if task.recurrence == 'biweekly' %}selected{% endif %}>Bi-weekly</option>
+        <option value="monthly" {% if task.recurrence == 'monthly' %}selected{% endif %}>Monthly</option>
+        <option value="yearly" {% if task.recurrence == 'yearly' %}selected{% endif %}>Yearly</option>
+        <option value="custom" {% if task.recurrence == 'custom' %}selected{% endif %}>Custom</option>
+    </select>
+</div>
+
+<input type="hidden" name="recurrence_rule" value="{{ task.recurrence_rule|default:'' }}">
+
+<div class="custom-recurrence-builder form-group {% if not task or task.recurrence != 'custom' %}hidden{% endif %}" style="background: var(--bg); border-radius: var(--radius-sm); padding: var(--space-md);">
+    <div class="form-group">
+        <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer; margin-bottom: var(--space-xs);">
+            <input type="radio" class="custom-freq-mode" value="weekly" onchange="toggleCustomFreqPanel(this)" {% if parsed.freq != 'monthly' %}checked{% endif %}>
+            Weekly
+        </label>
+        <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+            <input type="radio" class="custom-freq-mode" value="monthly" onchange="toggleCustomFreqPanel(this)" {% if parsed.freq == 'monthly' %}checked{% endif %}>
+            Monthly
+        </label>
+    </div>
+
+    <!-- Weekly panel -->
+    <div class="custom-weekly-panel {% if parsed.freq == 'monthly' %}hidden{% endif %}">
+        <div class="form-group">
+            <label class="form-label">Every
+                <input type="number" class="custom-interval" min="1" value="{{ parsed.interval|default:1 }}" style="width: 60px;">
+                week(s) on:
+            </label>
+            <div style="display: flex; flex-wrap: wrap; gap: var(--space-sm);">
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="SU" {% if "SU" in parsed.byweekday %}checked{% endif %}> Su
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="MO" {% if "MO" in parsed.byweekday %}checked{% endif %}> Mo
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="TU" {% if "TU" in parsed.byweekday %}checked{% endif %}> Tu
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="WE" {% if "WE" in parsed.byweekday %}checked{% endif %}> We
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="TH" {% if "TH" in parsed.byweekday %}checked{% endif %}> Th
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="FR" {% if "FR" in parsed.byweekday %}checked{% endif %}> Fr
+                </label>
+                <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                    <input type="checkbox" class="custom-weekday" value="SA" {% if "SA" in parsed.byweekday %}checked{% endif %}> Sa
+                </label>
+            </div>
+        </div>
+    </div>
+
+    <!-- Monthly panel -->
+    <div class="custom-monthly-panel {% if parsed.freq != 'monthly' %}hidden{% endif %}">
+        <div class="form-group">
+            <label class="form-label">Every
+                <input type="number" class="custom-interval" min="1" value="{{ parsed.interval|default:1 }}" style="width: 60px;">
+                month(s):
+            </label>
+        </div>
+
+        <div class="form-group">
+            <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer; margin-bottom: var(--space-xs);">
+                <input type="radio" class="custom-monthly-mode" value="day" {% if parsed.monthly_mode != 'nth' %}checked{% endif %}>
+                On day
+                <input type="number" class="custom-bymonthday" min="1" max="31" value="{{ parsed.bymonthday|default:1 }}" style="width: 60px;">
+                of the month
+            </label>
+            <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
+                <input type="radio" class="custom-monthly-mode" value="nth" {% if parsed.monthly_mode == 'nth' %}checked{% endif %}>
+                On the
+                <select class="custom-nth-ordinal form-select" style="width: auto;">
+                    <option value="1" {% if parsed.nth_ordinal == 1 %}selected{% endif %}>First</option>
+                    <option value="2" {% if parsed.nth_ordinal == 2 %}selected{% endif %}>Second</option>
+                    <option value="3" {% if parsed.nth_ordinal == 3 %}selected{% endif %}>Third</option>
+                    <option value="4" {% if parsed.nth_ordinal == 4 %}selected{% endif %}>Fourth</option>
+                    <option value="-1" {% if parsed.nth_ordinal == -1 %}selected{% endif %}>Last</option>
+                </select>
+                <select class="custom-nth-weekday form-select" style="width: auto;">
+                    <option value="SU" {% if parsed.nth_weekday == "SU" %}selected{% endif %}>Sunday</option>
+                    <option value="MO" {% if parsed.nth_weekday == "MO" %}selected{% endif %}>Monday</option>
+                    <option value="TU" {% if parsed.nth_weekday == "TU" %}selected{% endif %}>Tuesday</option>
+                    <option value="WE" {% if parsed.nth_weekday == "WE" %}selected{% endif %}>Wednesday</option>
+                    <option value="TH" {% if parsed.nth_weekday == "TH" %}selected{% endif %}>Thursday</option>
+                    <option value="FR" {% if parsed.nth_weekday == "FR" %}selected{% endif %}>Friday</option>
+                    <option value="SA" {% if parsed.nth_weekday == "SA" %}selected{% endif %}>Saturday</option>
+                </select>
+            </label>
+        </div>
+    </div>
+</div>
+{% endwith %}

templates/tasks/_task_detail.html

@@ -8,7 +8,7 @@
     </button>
 </div>
 
-<form method="post" action="{% url 'task-detail' task.id %}" id="task-detail-form">
+<form method="post" action="{% url 'task-detail' task.id %}" id="task-detail-form" onsubmit="assembleCustomRecurrenceRule(this)">
     {% csrf_token %}
     <input type="hidden" name="next" value="{% url 'dashboard' %}?selected={{ task.id }}{% if request.GET.filter %}&filter={{ request.GET.filter }}{% endif %}{% if request.GET.tag %}&tag={{ request.GET.tag }}{% endif %}">
 
@@ -75,18 +75,7 @@
     </div>
     {% endif %}
 
-    <!-- Recurrence -->
-    <div class="form-group">
-        <label class="form-label" for="detail-recurrence">Recurrence</label>
-        <select class="form-select" id="detail-recurrence" name="recurrence">
-            <option value="none" {% if task.recurrence == 'none' %}selected{% endif %}>None</option>
-            <option value="daily" {% if task.recurrence == 'daily' %}selected{% endif %}>Daily</option>
-            <option value="weekly" {% if task.recurrence == 'weekly' %}selected{% endif %}>Weekly</option>
-            <option value="biweekly" {% if task.recurrence == 'biweekly' %}selected{% endif %}>Bi-weekly</option>
-            <option value="monthly" {% if task.recurrence == 'monthly' %}selected{% endif %}>Monthly</option>
-            <option value="yearly" {% if task.recurrence == 'yearly' %}selected{% endif %}>Yearly</option>
-        </select>
-    </div>
+    {% include 'tasks/_recurrence_fields.html' with id_prefix='detail-' task=task %}
 
     <!-- Save Button (moved inside form, before subtasks) -->
     <div class="detail-actions" style="margin-bottom: var(--space-lg);">

templates/tasks/dashboard.html

@@ -9,7 +9,6 @@
     <div style="display: flex; align-items: center; gap: var(--space-md);">
         <span class="task-count">{{ tasks|length }} task{{ tasks|length|pluralize }}</span>
         <select id="sort-select" onchange="updateSort()" style="padding: 4px 8px; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--surface); color: var(--text);">
-            <option value="default" {% if current_sort == 'default' %}selected{% endif %}>Default</option>
             <option value="due_date" {% if current_sort == 'due_date' %}selected{% endif %}>Due Date (Earliest)</option>
             <option value="due_date_desc" {% if current_sort == 'due_date_desc' %}selected{% endif %}>Due Date (Latest)</option>
             <option value="priority" {% if current_sort == 'priority' %}selected{% endif %}>Priority (High to Low)</option>
@@ -76,7 +75,7 @@ if (timerDisplay) {
 function updateSort() {
     const sortValue = document.getElementById('sort-select').value;
     const url = new URL(window.location.href);
-    if (sortValue === 'default') {
+    if (sortValue === 'due_date') {
         url.searchParams.delete('sort');
     } else {
         url.searchParams.set('sort', sortValue);

templates/tasks/task_create.html

@@ -10,7 +10,7 @@
 </div>
 
 <div style="background: var(--surface); border-radius: var(--radius-md); padding: var(--space-xl); max-width: 600px;">
-    <form method="post">
+    <form method="post" onsubmit="assembleCustomRecurrenceRule(this)">
         {% csrf_token %}
 
         <div class="form-group">
@@ -55,17 +55,7 @@
             </div>
         </div>
 
-        <div class="form-group">
-            <label class="form-label" for="recurrence">Recurrence</label>
-            <select class="form-select" id="recurrence" name="recurrence">
-                <option value="none" selected>None</option>
-                <option value="daily">Daily</option>
-                <option value="weekly">Weekly</option>
-                <option value="biweekly">Bi-weekly</option>
-                <option value="monthly">Monthly</option>
-                <option value="yearly">Yearly</option>
-            </select>
-        </div>
+        {% include 'tasks/_recurrence_fields.html' with id_prefix='' %}
 
         {% if tags %}
         <div class="form-group">

templates/tasks/task_detail.html

@@ -19,7 +19,7 @@
 <div style="display: grid; grid-template-columns: 1fr 350px; gap: var(--space-lg);">
     <!-- Main Form -->
     <div style="background: var(--surface); border-radius: var(--radius-md); padding: var(--space-xl);">
-        <form method="post">
+        <form method="post" onsubmit="assembleCustomRecurrenceRule(this)">
             {% csrf_token %}
 
             <div class="form-group">
@@ -81,31 +81,7 @@
             </div>
             {% endif %}
 
-            <div class="form-group">
-                <label class="form-label" for="recurrence">Recurrence</label>
-                <select class="form-select" id="recurrence" name="recurrence">
-                    <option value="none" {% if task.recurrence == 'none' %}selected{% endif %}>None</option>
-                    <option value="daily" {% if task.recurrence == 'daily' %}selected{% endif %}>Daily</option>
-                    <option value="weekly" {% if task.recurrence == 'weekly' %}selected{% endif %}>Weekly</option>
-                    <option value="biweekly" {% if task.recurrence == 'biweekly' %}selected{% endif %}>Bi-weekly</option>
-                    <option value="monthly" {% if task.recurrence == 'monthly' %}selected{% endif %}>Monthly</option>
-                    <option value="yearly" {% if task.recurrence == 'yearly' %}selected{% endif %}>Yearly</option>
-                </select>
-            </div>
-
-            {% if tags %}
-            <div class="form-group">
-                <label class="form-label">Tags</label>
-                <div style="display: flex; flex-wrap: wrap; gap: var(--space-sm);">
-                    {% for tag in tags %}
-                    <label style="display: flex; align-items: center; gap: var(--space-xs); cursor: pointer;">
-                        <input type="checkbox" name="tags" value="{{ tag.id }}" {% if tag in task.tags.all %}checked{% endif %}>
-                        <span style="color: {{ tag.color }}">{{ tag.name }}</span>
-                    </label>
-                    {% endfor %}
-                </div>
-            </div>
-            {% endif %}
+            {% include 'tasks/_recurrence_fields.html' with id_prefix='' task=task %}
 
             <button type="submit" class="btn btn-primary">Save Changes</button>
         </form>

templates/users/login.html

@@ -33,8 +33,10 @@
         <button type="submit" class="btn btn-primary btn-full">Login</button>
     </form>
 
+    {% if allow_self_registration %}
     <p class="auth-footer">
         Don't have an account? <a href="{% url 'register' %}">Register</a>
     </p>
+    {% endif %}
 </div>
 {% endblock %}

templates/users/profile.html

@@ -18,7 +18,7 @@
 <div class="card" style="background: var(--surface); padding: 1.5rem; border-radius: 0.75rem; margin-bottom: 1.5rem; border: 1px solid var(--border);">
     <h2 style="font-size: 1.25rem; font-weight: 600; margin-bottom: 1.5rem;">Personal Information</h2>
 
-    <form method="post">
+    <form method="post" onsubmit="handleProfileFormSubmit(event, this)">
         {% csrf_token %}
 
         <div style="display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin-bottom: 1.5rem;">
@@ -96,6 +96,7 @@
             <label style="display: flex; align-items: center; cursor: pointer; padding: 0.75rem; background: var(--surface); border: 1px solid var(--border); border-radius: 0.375rem;">
                 <input type="checkbox"
                        name="push_notifications"
+                       data-vapid-public-key="{{ vapid_public_key }}"
                        {% if user.push_notifications %}checked{% endif %}
                        style="margin-right: 0.75rem; width: 1rem; height: 1rem;">
                 <div>

users/management/commands/generate_vapid_keys.py

@@ -0,0 +1,36 @@
+"""
+Generate a VAPID keypair for Web Push notifications.
+
+Uses `cryptography` directly rather than py_vapid's own Vapid02.generate_keys(),
+which raises `TypeError: curve must be an EllipticCurve instance` against
+newer versions of `cryptography` (confirmed with cryptography 46.0.3 / py-vapid 1.9.2).
+"""
+
+import base64
+
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives import serialization
+from django.core.management.base import BaseCommand
+
+
+class Command(BaseCommand):
+    help = 'Generate a VAPID public/private keypair for Web Push notifications'
+
+    def handle(self, *args, **options):
+        private_key = ec.generate_private_key(ec.SECP256R1())
+        public_key = private_key.public_key()
+
+        private_value = private_key.private_numbers().private_value
+        private_bytes = private_value.to_bytes(32, 'big')
+        private_b64 = base64.urlsafe_b64encode(private_bytes).rstrip(b'=').decode()
+
+        public_bytes = public_key.public_bytes(
+            encoding=serialization.Encoding.X962,
+            format=serialization.PublicFormat.UncompressedPoint,
+        )
+        public_b64 = base64.urlsafe_b64encode(public_bytes).rstrip(b'=').decode()
+
+        self.stdout.write('Add these to your environment configuration:\n')
+        self.stdout.write(f'VAPID_PUBLIC_KEY={public_b64}')
+        self.stdout.write(f'VAPID_PRIVATE_KEY={private_b64}')
+        self.stdout.write('VAPID_ADMIN_EMAIL=<your admin contact email>')

users/models.py

@@ -57,6 +57,39 @@ class User(AbstractUser):
     def __str__(self):
         return self.email
 
+    @classmethod
+    def from_db(cls, db, field_names, values):
+        instance = super().from_db(db, field_names, values)
+        instance._loaded_default_reminder_minutes = dict(zip(field_names, values)).get('default_reminder_minutes')
+        return instance
+
+    def save(self, *args, **kwargs):
+        loaded_reminder_minutes = getattr(self, '_loaded_default_reminder_minutes', None)
+        reminder_minutes_changed = (
+            loaded_reminder_minutes is not None and loaded_reminder_minutes != self.default_reminder_minutes
+        )
+
+        super().save(*args, **kwargs)
+        self._loaded_default_reminder_minutes = self.default_reminder_minutes
+
+        if reminder_minutes_changed:
+            self.reschedule_reminder_notifications()
+
+    def reschedule_reminder_notifications(self):
+        """
+        Recompute "before due" reminders for active tasks using the current
+        default_reminder_minutes. Task.reschedule_reminders() only captures
+        this setting at the moment a task's own due_date/due_time is set,
+        so it doesn't apply retroactively on its own - this is what makes a
+        profile-level change to the setting reach existing tasks. Tasks
+        with their own explicit reminder_at override are left alone.
+        """
+        tasks = self.tasks.filter(
+            due_date__isnull=False, is_deleted=False, reminder_at__isnull=True,
+        ).exclude(status__in=('completed', 'cancelled'))
+        for task in tasks:
+            task.reschedule_reminders()
+
 
 class DeviceToken(models.Model):
     """

users/views.py

@@ -3,6 +3,7 @@ User views for KeepItGoing.
 """
 
 from django.contrib.auth import get_user_model, login, logout
+from django.conf import settings
 from django.shortcuts import render, redirect
 from django.utils import timezone
 from django.views import View
@@ -27,6 +28,13 @@ from .throttles import LoginRateThrottle, RegisterRateThrottle
 User = get_user_model()
 
 
+def self_registration_disabled_response():
+    """Standard response payload for disabled self-registration."""
+    return {
+        'detail': 'Self-registration is disabled. Contact an administrator to create your account.'
+    }
+
+
 # =============================================================================
 # API Views
 # =============================================================================
@@ -36,18 +44,18 @@ class UsersAPIRoot(APIView):
     permission_classes = [permissions.AllowAny]
 
     def get(self, request):
-        return Response({
-            'endpoints': {
-                'register': '/api/users/register/',
-                'login': '/api/users/token/',
-                'refresh_token': '/api/users/token/refresh/',
-                'verify_email': '/api/users/verify-email/',
-                'resend_verification': '/api/users/resend-verification/',
-                'profile': '/api/users/profile/',
-                'change_password': '/api/users/change-password/',
-                'devices': '/api/users/devices/',
-            }
-        })
+        endpoints = {
+            'login': '/api/users/token/',
+            'refresh_token': '/api/users/token/refresh/',
+            'verify_email': '/api/users/verify-email/',
+            'resend_verification': '/api/users/resend-verification/',
+            'profile': '/api/users/profile/',
+            'change_password': '/api/users/change-password/',
+            'devices': '/api/users/devices/',
+        }
+        if settings.ALLOW_SELF_REGISTRATION:
+            endpoints['register'] = '/api/users/register/'
+        return Response({'endpoints': endpoints})
 
 
 class RegisterAPIView(generics.CreateAPIView):
@@ -59,6 +67,12 @@ class RegisterAPIView(generics.CreateAPIView):
     throttle_classes = [RegisterRateThrottle]
 
     def create(self, request, *args, **kwargs):
+        if not settings.ALLOW_SELF_REGISTRATION:
+            return Response(
+                self_registration_disabled_response(),
+                status=status.HTTP_403_FORBIDDEN
+            )
+
         serializer = self.get_serializer(data=request.data)
         serializer.is_valid(raise_exception=True)
         user = serializer.save()
@@ -284,6 +298,7 @@ class LoginView(View):
             'error': error,
             'email': email,
             'can_resend': can_resend,
+            'allow_self_registration': settings.ALLOW_SELF_REGISTRATION,
         })
 
     def post(self, request):
@@ -319,6 +334,7 @@ class LoginView(View):
             'error': error,
             'email': email,
             'can_resend': can_resend,
+            'allow_self_registration': settings.ALLOW_SELF_REGISTRATION,
         })
 
 
@@ -340,9 +356,20 @@ class RegisterView(View):
     def get(self, request):
         if request.user.is_authenticated:
             return redirect('dashboard')
+        if not settings.ALLOW_SELF_REGISTRATION:
+            return render(request, 'users/login.html', {
+                'error': 'Self-registration is disabled. Contact an administrator to create your account.',
+                'allow_self_registration': False,
+            }, status=403)
         return render(request, 'users/register.html')
 
     def post(self, request):
+        if not settings.ALLOW_SELF_REGISTRATION:
+            return render(request, 'users/login.html', {
+                'error': 'Self-registration is disabled. Contact an administrator to create your account.',
+                'allow_self_registration': False,
+            }, status=403)
+
         email = request.POST.get('email')
         username = request.POST.get('username')
         password = request.POST.get('password')
@@ -397,7 +424,9 @@ class ProfileView(View):
     def get(self, request):
         if not request.user.is_authenticated:
             return redirect('login')
-        return render(request, 'users/profile.html')
+        return render(request, 'users/profile.html', {
+            'vapid_public_key': settings.VAPID_PUBLIC_KEY,
+        })
 
     def post(self, request):
         if not request.user.is_authenticated:
@@ -413,7 +442,8 @@ class ProfileView(View):
         user.save()
 
         return render(request, 'users/profile.html', {
-            'success': 'Profile updated successfully.'
+            'success': 'Profile updated successfully.',
+            'vapid_public_key': settings.VAPID_PUBLIC_KEY,
         })