# Phase 4: Reminders & Calendar Extension
**Timeline: Weeks 17-22**

This phase focuses on implementing the Reminders & Calendar functionality with potential integration with the Goal Planner extension.

## Week 17-18: Reminders System Implementation

### Time-based Reminders
- [ ] Design reminder data structure and schema
- [ ] Implement reminder creation interface
- [ ] Develop reminder editing and deletion
- [ ] Create time-based triggering system
- [ ] Build notification delivery mechanism

### Recurring Reminders
- [ ] Implement recurring pattern definition
- [ ] Create daily/weekly/monthly/yearly options
- [ ] Develop custom recurrence patterns
- [ ] Build exception handling for recurrence
- [ ] Design recurrence preview and validation

### Notification System
- [ ] Implement multi-platform notifications
- [ ] Create notification customization options
- [ ] Develop notification acknowledgment tracking
- [ ] Build notification snooze functionality
- [ ] Design notification grouping and batching

### Priority and Categorization
- [ ] Implement priority levels for reminders
- [ ] Create category management for reminders
- [ ] Develop filtering by priority and category
- [ ] Build sorting options for reminder lists
- [ ] Design visual indicators for priority levels

## Week 19-20: Calendar Interface Development

### Calendar View
- [ ] Design and implement monthly calendar view
- [ ] Create weekly and daily view options
- [ ] Develop agenda/list view alternative
- [ ] Build view customization options
- [ ] Implement print and export functionality

### Event Management
- [ ] Implement event creation interface
- [ ] Create event editing and deletion
- [ ] Develop all-day vs. time-specific events
- [ ] Build multi-day event handling
- [ ] Design event details and description

### Timeline Visualization
- [ ] Create visual timeline of upcoming events
- [ ] Implement zooming and scrolling
- [ ] Develop filtering and customization
- [ ] Build event clustering for busy periods
- [ ] Design color coding by category/source

### Location-based Alerts
- [ ] Implement location awareness (if appropriate)
- [ ] Create geofencing for location triggers
- [ ] Develop location suggestion and search
- [ ] Build favorite locations management
- [ ] Design privacy controls for location data

## Week 21-22: Goal Planner Integration

### Unified Interface
- [ ] Design combined goal and reminder view
- [ ] Implement visual integration between systems
- [ ] Create consistent interaction patterns
- [ ] Build navigation between related items
- [ ] Develop unified search across both systems

### Synchronized View
- [ ] Implement goal deadlines as calendar events
- [ ] Create milestone visualization on calendar
- [ ] Develop progress tracking within calendar
- [ ] Build reminder creation from goals
- [ ] Design visual distinction between types

### AI Scheduling Suggestions
- [ ] Integrate AI for optimal scheduling
- [ ] Create time allocation recommendations
- [ ] Develop conflict detection and resolution
- [ ] Build workload balancing suggestions
- [ ] Design goal-aligned time management

### Time Blocking
- [ ] Implement time blocking interface
- [ ] Create block customization and templates
- [ ] Develop recurring time blocks
- [ ] Build productivity analytics for blocks
- [ ] Design block visualization on calendar

### Integration Testing
- [ ] Test goal-calendar synchronization
- [ ] Verify notification delivery
- [ ] Validate data consistency between systems
- [ ] Ensure performance with large datasets
- [ ] Confirm backup and restore functionality

## Final Deliverables Checklist

### Reminders System
- [ ] Reminder creation and management works correctly
- [ ] Recurring reminders function as expected
- [ ] Notifications are delivered reliably
- [ ] Priority and categorization are effective
- [ ] User can easily manage their reminders

### Calendar Functionality
- [ ] Calendar view displays events clearly
- [ ] Event management is intuitive
- [ ] Timeline provides useful upcoming view
- [ ] Location-based features work as intended
- [ ] Calendar data can be exported/shared

### Goal Planner Integration
- [ ] Unified interface is cohesive and intuitive
- [ ] Synchronized view shows relevant information
- [ ] AI suggestions are helpful for scheduling
- [ ] Time blocking enhances productivity
- [ ] Systems work together without conflicts

### Documentation
- [ ] Reminders & Calendar features are documented
- [ ] Integration with Goal Planner is explained
- [ ] Best practices for time management are included
- [ ] Export and sharing options are described
- [ ] Privacy considerations for location are addressed

## Development Standards
- Ensure reliable notification delivery across platforms
- Test timezone handling thoroughly
- Optimize calendar rendering for performance
- Create comprehensive tests for recurring pattern logic
- Document all reminder and calendar interfaces
- Test with realistic usage patterns and data volumes