- Add enhanced due date filtering to get_todos function with support for "today", "this_week", "next_week"
- Add overdue filtering parameter with timezone-aware comparisons
- Add sorting by due_date with null values at end
- Add get_overdue_todos function for retrieving overdue todos
- Add get_todos_due_soon function for todos due within next N days (default 7)
- Add get_todos_by_date_range function for custom date range filtering
- Create comprehensive date utilities in app/utils/date_utils.py with timezone support
- Add project_id and tag_ids support to TodoCreate and TodoUpdate schemas
- Include efficient database indexing for due_date queries
- Use SQLAlchemy timezone-aware datetime filtering throughout
- Add proper overdue detection logic with timezone handling