- Fix timezone field display in event modals to show original timezone from server
- Fix formatDateToICal to use moment.utc(date).tz(timezone) for correct UTC instant preservation
- Fix parseCalendarEvent to convert event.start/end to ISO UTC strings after parsing
- Fix eventToFullCalendarFormat to ensure event times are ISO UTC before passing to FullCalendar
- Fix getEvent to normalize event.start/end to ISO UTC strings
- Ensure event.timezone is always set (defaults to Etc/UTC if not detected)
- Update eventUtils.test.ts to match new timezone conversion logic
- Fix event time shift issue on calendar grid display
This ensures:
- Events display in correct time slots on calendar grid
- Event times are correctly converted between timezones
- Original timezone from server is preserved and displayed
- All event times are stored as ISO UTC strings internally
* refactor: eliminate datetime format detection code duplication
- Add constants for datetime format strings and magic number (DATETIME_WITH_SECONDS_LENGTH, DATETIME_FORMAT_WITH_SECONDS, DATETIME_FORMAT_WITHOUT_SECONDS)
- Create shared detectDateTimeFormat() function to replace duplicated format detection logic
- Refactor convertFormDateTimeToISO, convertEventDateTimeToISO, and convertDateTimeStringToISO to use shared helper
- Add console.warn logging when invalid datetime is encountered (addresses silent fallback issue)
- Add comprehensive test coverage for dateTimeHelpers with full test suite
lethemanh