Google Apps Script to sync personal calendar with work calendar

AppScriptCalendarSync.gs

/**
Google Drive > New > Apps Script
Paste below into Code.gs file
On the left sidebar, look for triggers menu to add a time-based trigger.
*/

const ID = "" // FILL IN secondary calendar ID
const EVENT_NAME = "busy (autosync)" // change event name
const DAYS_TO_SYNC = [1,2,3,4,5] // add 6, 7 to monitor weekends too
const DAYS_BUFFER = 14 // how many days in advance to monitor

function sync() {
  var secondaryCal=CalendarApp.getCalendarById(ID);
  var today=new Date();
  var enddate=new Date();
  enddate.setDate(today.getDate()+DAYS_BUFFER);
  var secondaryEvents=secondaryCal.getEvents(today,enddate).filter(e => DAYS_TO_SYNC.includes(e.getStartTime().getDay()));

  var primaryCal=CalendarApp.getDefaultCalendar();
  
  var primaryEvents=primaryCal.getEvents(today,enddate);

  // delete previously synced events if they no longer exist in the secondary calendar
  var previouslySynced = primaryEvents.filter(e => e.getTitle() == EVENT_NAME)
  for (const prev of previouslySynced) {
    if (!secondaryEvents.includes(se => se.getStartTime() === prev.getStartTime() && se.getEndTime() === prev.getEndTime())) {
      prev.deleteEvent();
    }
  }
 
  for (const se of secondaryEvents)
  {
    if (primaryEvents.includes(p => p.getStartTime() == se.getStartTime() && p.getEndTime() == se.getEndTime() && p.getTitle() == EVENT_NAME)) continue;

    if (se.isAllDayEvent()) continue;

    // secondary calendar owner not going
    if (se.getGuestByEmail(ID)?.getGuestStatus()?.toString() === "NO") continue;
    
    // no one else going
    const guests = se.getGuestList();
    if(guests.length > 0 && guests.every(g => g.getGuestStatus().toString() === "NO")) continue;
  

    var newEvent = primaryCal.createEvent(EVENT_NAME,se.getStartTime(),se.getEndTime());
    // alternative version below that copies the exact secondary event information into the primary calendar event
    // var newEvent = primaryCal.createEvent(se.getTitle(),se.getStartTime(),se.getEndTime(), {location: se.getLocation(), description: se.getDescription()});  

     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

  }

}