Google App Script to decline events over a date range

google_calendar_mass_decline.js

// https://www.jasonmadigan.com/2017/07/03/declining-google-calendar-events-en-masse/

function GCalHoliday() {
  var fromDate = new Date('July 17, 2017 00:00:00 +0100');
  var toDate = new Date('August 8, 2017 23:30:00 +0100');
  var calendarName = '<Your Calendar - e.g. [email protected]>';

  var calendar = CalendarApp.getCalendarsByName(calendarName)[0];
  var events = calendar.getEvents(fromDate, toDate, {});
  Logger.log('Events: ' + events.length);

  for (var i = 0; i < events.length; i++) {
    var ev = events[i];
    // try/catch for setting status - may get exceptions where events 
    // are on calendar, but user is not a "guest" of the event - these can be ignored
    try {
      // !!!
      // ev.setMyStatus(CalendarApp.GuestStatus.NO); // Uncomment to actually update status
      // !!!
    } catch (e) {
      Logger.log('Error updating event status ' + e);
    }
    Logger.log('Item ' + ev.getTitle() + ' found on ' + ev.getStartTime() + ' marked as declined');
  }
}