public function getCalendarDate(Request $request)
 {
     $month = date('m', strtotime($request->date));
     $year = date('Y', strtotime($request->date));
     $end_day_month = date("t", strtotime($request->date));
     $filter_start_date = $year . '-' . $month . '-01';
     $filter_end_date = $year . '-' . $month . '-' . $end_day_month;
     $calendars = Calendar::whereBetween('start_date', array($filter_start_date, $filter_end_date))->get();
     return response()->json($calendars);
 }