- Introduced TIMEZONES constant in models.py to store valid timezone options.
- Updated Visit, Transportation, and Lodging models to include timezone fields.
- Modified serializers to include timezone fields in VisitSerializer, TransportationSerializer, and LodgingSerializer.
- Enhanced DateRangeCollapse component to handle timezone selection and formatting.
- Implemented timezone formatting functions in LodgingCard and TransportationCard components.
- Updated LodgingModal and TransportationModal to bind timezone data.
- Added VALID_TIMEZONES to dateUtils for consistent timezone management across the application.
