public function actionAddHalfYear()
 {
     $start = null;
     $interval = null;
     $end = null;
     if (!empty($_POST['start_dt'])) {
         $start = $_POST['start_dt'];
     }
     if (!empty($_POST['interval'])) {
         $interval = $_POST['interval'];
     }
     if (!empty($_POST['end_dt'])) {
         $end = $_POST['end_dt'];
     }
     echo UserFunctions::addFalfYear($start, $interval, $end);
 }