bff1af31bd
- 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