public function addClassDetail($classId, $classroomId, $teacherId, $date, $startTime, $endTime)
 {
     try {
         $tId = session('instId');
         $dayOfWeek = date('w', strtotime($date));
         //get the dayOfWeek of this timestamp
         if ($dayOfWeek == 0) {
             $dayOfWeek = 7;
         }
         $ymd = explode('-', $date);
         $year = $ymd[0];
         $month = $ymd[1];
         $startTimeInt = str_replace(':', '', $startTime);
         //save class detail
         $class = new \Home\Model\ClassModel();
         $classDetailId = $class->saveClassDetail($date, $year, $month, $dayOfWeek, $startTime, (int) $startTimeInt, $endTime, $teacherId, $classroomId, $classId, $tId);
         $data = "true";
     } catch (Exception $e) {
         $data = "false";
     }
     $this->ajaxReturn($data);
 }