google-calendar-sync.gs

// Google Script usable to setup and run via a trigger on https://script.google.com/
//
// Main goal is to sync personal events from the personal calendar as busy events
// in the work calendar. 

function syncPersonalToTeam() {
  const personalId = 'personal@gmail.com';
  const workId = 'work@gmail.com';
  const teamId = 'team_id@group.calendar.google.com';
  const now = new Date();
  const future = new Date();
  future.setDate(now.getDate() + 30);
  
  const personal = CalendarApp.getCalendarById(personalId);
  const work = CalendarApp.getCalendarById(workId);
  const team = CalendarApp.getCalendarById(teamId);
  const eventTitle = "Adrian Lungu Busy"
  const eventDayTitle = "Adrian Lungu Day Off"

  const allowedAllDayTypes = [
    CalendarApp.EventType.OUT_OF_OFFICE,
    CalendarApp.EventType.DEFAULT,
    CalendarApp.EventType.FOCUS_TIME,
  ];
  
  // Sync personal events completely
  const events = personal.getEvents(now, future);
  events.forEach(event => {
    const existing = team.getEvents(event.getStartTime(), event.getEndTime(), { search: eventTitle });
    if (existing.length === 0) {
      Logger.log('%s: %s - %s; %s; %s', event.getTitle(), event.getStartTime(), event.getEndTime(), event.isAllDayEvent(), event.getEventType());

      team.createEvent(eventTitle, event.getStartTime(), event.getEndTime());
    }
  });

  // Sync only full day work events
  const eventsWork = work.getEvents(now, future);
  eventsWork.forEach(event => {    
    // Skip non-matching types like WORKING_LOCATION, BIRTHDAY etc; and also 
    if (!allowedAllDayTypes.includes(event.getEventType())) return;

    // Check if it's an all day event 
    if (!isVisuallyAllDay(event)) return;

    Logger.log('%s: %s - %s; %s; %s', event.getTitle(), event.getStartTime(), event.getEndTime(), event.isAllDayEvent(), event.getEventType());

    const workEventTitle = event.getTitle();
    var startDate = new Date()
    var endDate = new Date()

    if (event.isAllDayEvent()) {
      startDate = event.getAllDayStartDate();
      endDate = event.getAllDayEndDate();
    } else {
      startDate = event.getStartTime();
      endDate = event.getEndTime();
    }


    const existing = team.getEventsForDay(startDate).find(e => 
      e.isAllDayEvent() &&
      e.getTitle() === eventDayTitle &&
      e.getAllDayStartDate().getTime() === startDate.getTime() &&
      e.getAllDayEndDate().getTime() === endDate.getTime()
    );

    if (!existing) {
      team.createAllDayEvent(eventDayTitle, startDate, endDate, {
        description: event.getDescription(),
        location: event.getLocation()
      });
    }
  });

}

function isVisuallyAllDay(event) {
  if (event.isAllDayEvent()) return true;

  const start = event.getStartTime();
  const end = event.getEndTime();

  // Check: starts at midnight, ends at midnight + whole-day multiple
  const isAlignedToMidnight =
    start.getHours() === 0 && start.getMinutes() === 0 &&
    end.getHours() === 0 && end.getMinutes() === 0;

  const duration = end - start; // in ms
  const isWholeDay = duration % (24 * 60 * 60 * 1000) === 0;

  return isAlignedToMidnight && isWholeDay;
}