google_calendar_holiday.gs

function googleCalendarHoliday() {
  var fromDate = new Date('2017-12-19T00:00:00-08:00');
  var toDate = new Date('2018-01-01T23:30:00-08:00');
  var calendarId = "your@gmail";
  //Logger.log(CalendarApp.getAllCalendars().map(function(c) { return c.getId() }));
  var calendar = CalendarApp.getCalendarById(calendarId);
  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.removeAllReminders();
      ev.setMyStatus(CalendarApp.GuestStatus.NO);
      // !!!
    } catch (e) {
      Logger.log('Error updating event status of ' + ev.getTitle() + ": " + e);
    }
    //Logger.log('Item ' + ev.getTitle() + ' found on ' + ev.getStartTime() + ' marked as declined');
  }
}