google-calendar-sync

sync.gs

function sync() {

  var id="XXXX"; // CHANGE - id of the secondary calendar to pull events from

  var today=new Date();
  var enddate=new Date();
  enddate.setDate(today.getDate()+15); // how many days in advance to monitor and block off time
  
  var secondaryCal=CalendarApp.getCalendarById(id);
  var secondaryEvents=secondaryCal.getEvents(today,enddate);
  
  var primaryCal=CalendarApp.getDefaultCalendar();
  var primaryEvents=primaryCal.getEvents(today,enddate); // all primary calendar events
  
  var primaryEventTitle="OOO"; // update this to the text you'd like to appear in the new events created in primary calendar
  
  var stat=1;
  var evi, existingEvent; 
  var primaryEventsFiltered = []; // to contain primary calendar events that were previously created from secondary calendar
  var primaryEventsUpdated = []; // to contain primary calendar events that were updated from secondary calendar
  var primaryEventsCreated = []; // to contain primary calendar events that were created from secondary calendar
  var primaryEventsDeleted = []; // to contain primary calendar events previously created that have been deleted from secondary calendar

  Logger.log('Number of primaryEvents: ' + primaryEvents.length);  
  Logger.log('Number of secondaryEvents: ' + secondaryEvents.length);
  
  // create filtered list of existing primary calendar events that were previously created from the secondary calendar
  for (pev in primaryEvents)
  {
    var pEvent = primaryEvents[pev];
    if (pEvent.getTitle() == primaryEventTitle)
    { primaryEventsFiltered.push(pEvent); }
  }
  
  // process all events in secondary calendar
  for (sev in secondaryEvents)
  {
    stat=1;
    evi=secondaryEvents[sev];
    
    // if the secondary event has already been blocked in the primary calendar, update it
    for (existingEvent in primaryEventsFiltered)
      {
        var pEvent = primaryEventsFiltered[existingEvent];
        var secondaryTitle = evi.getTitle();
        var secondaryDesc = evi.getDescription();
        if ((pEvent.getStartTime().getTime()==evi.getStartTime().getTime()) && (pEvent.getEndTime().getTime()==evi.getEndTime().getTime()))
        {
          stat=0;
          pEvent.setTitle(primaryEventTitle);
          pEvent.setDescription(secondaryTitle + '\n\n' + secondaryDesc);
          // event.setDescription(evi.getTitle() + '\n\n' + evi.getDescription());
          pEvent.setVisibility(CalendarApp.Visibility.PRIVATE); // set blocked time as private appointments in work calendar
          primaryEventsUpdated.push(pEvent.getId());
          Logger.log('PRIMARY EVENT UPDATED'
                     + '\nprimaryId: ' + pEvent.getId() + ' \nprimaryTitle: ' + pEvent.getTitle() + ' \nprimaryDesc: ' + pEvent.getDescription());
        } 
      }

    if (stat==0) continue;    
    
    var d = evi.getStartTime();
    var n = d.getDay();

    if (evi.isAllDayEvent())
    {
      continue; // Do nothing if the event is an all-day or multi-day event. This script only syncs hour-based events
    }
    else if (n==1 || n==2 || n==3 || n==4 || n==5) // skip weekends. Delete this if you want to include weekends
    // if the secondary event does not exist in the primary calendar, create it
    {
      //var description = evi.getTitle() + '\n\n' + evi.getDescription();
      
      // Creates Out Of Office events using the Calendar Service
      var newEvent = createOutOfOffice(primaryCal.getId(), evi.getStartTime(), evi.getEndTime(), primaryEventTitle);
      
      // Creates event using the Calendar Client
      /*
      var newEvent = primaryCal.createEvent(primaryEventTitle,evi.getStartTime(),evi.getEndTime()); // change the Booked text to whatever you would like your merged event titles to be
      // alternative version below that copies the exact secondary event information into the primary calendar event
      // var newEvent = primaryCal.createEvent(evi.getTitle(),evi.getStartTime(),evi.getEndTime(), {location: evi.getLocation(), description: evi.getDescription()});  
      newEvent.setDescription(description);
      newEvent.setVisibility(CalendarApp.Visibility.PRIVATE); // set blocked time as private appointments in work calendar
      newEvent.removeAllReminders(); // so you don't get double notifications. Delete this if you want to keep the default reminders for your newly created primary calendar events
      primaryEventsCreated.push(newEvent.getId());
      Logger.log('PRIMARY EVENT CREATED'
                 + '\nprimaryId: ' + newEvent.getId() + '\nprimaryTitle: ' + newEvent.getTitle() + '\nprimaryDesc ' + newEvent.getDescription() + '\n');
      */
    }
  }

  // if a primary event previously created no longer exists in the secondary calendar, delete it
  for (pev in primaryEventsFiltered)
  {
    var pevIsUpdatedIndex = primaryEventsUpdated.indexOf(primaryEventsFiltered[pev].getId());
    if (pevIsUpdatedIndex == -1)
    { 
      var pevIdToDelete = primaryEventsFiltered[pev].getId();
      Logger.log(pevIdToDelete + ' deleted');
      primaryEventsDeleted.push(pevIdToDelete);
      primaryEventsFiltered[pev].deleteEvent();
    }
  }  

  Logger.log('Primary events previously created: ' + primaryEventsFiltered.length);
  Logger.log('Primary events updated: ' + primaryEventsUpdated.length);
  Logger.log('Primary events deleted: ' + primaryEventsDeleted.length);
  Logger.log('Primary events created: ' + primaryEventsCreated.length);

}

// Creates Out Of Office events using the Calendar Service
function createOutOfOffice(calendarId, start, end, summary = 'OOO') {
  // event details for creating event.
  let event = {
    summary: summary, // Replace this with whatever name you want for the out of office events
    start: {
      dateTime: start.toISOString()
    },
    end: {
      dateTime: end.toISOString()
    },
    eventType: 'outOfOffice',
    outOfOfficeProperties: {
      autoDeclineMode: 'declineOnlyNewConflictingInvitations',
      declineMessage: 'Out of Office',
    }
  };
  try {
    // call method to insert/create new event in provided calandar
    event = Calendar.Events.insert(event, calendarId);
    Logger.log('Primary Event Created' + '\id: ' + event.id + '\ntitle: ' + event.summary);
    return event;
  } catch (err) {
    console.log('Failed with error %s', err.message);
  }
}

Setup

1. Share your personal calendar with your work account (remember to accept the calendar in your work account)
2. Copy your personal calendar id Settings and sharing > Integrate Calendar
3. Create a new Google App Script project under your work account
4. Paste this script and replace the id variable with your personal calendar id
5. Add Calendar service to the project
6. Save and run the script once (it will ask for permissions to access your calendar)
7. Add a trigger (left sidebar) to run the script on every personal calendar update