/**
  * @return \yii\db\ActiveQuery
  */
 public function getTimetable()
 {
     return $this->hasOne(Timetable::className(), ['id' => 'timetable_id']);
 }
 public function rules()
 {
     return [[['id', 'date'], 'required'], ['id', 'integer', 'min' => 1], ['id', 'exist', 'targetAttribute' => 'id', 'targetClass' => Timetable::className()], ['date', 'match', 'pattern' => '/^(20)\\d\\d[-](0[1-9]|1[012])[-](0[1-9]|[12][0-9]|3[01])$/']];
 }