public function actionShifts($id = null)
 {
     if (!isset($id)) {
         $id = Yii::$app->params['currentEvent'];
     }
     $data = Participant::findUserEventDataByDay($id, Yii::$app->user->id);
     $events = Event::find()->where(['not', ['id' => $id]])->all();
     return $this->render('shifts', ['data' => $data, 'event' => Event::findOne($id), 'events' => $events]);
 }