Bolt\Storage\Field\Type\DateType::persist PHP Метод

    public function persist(QuerySet $queries, $entity)
    {
        $key = $this->mapping['fieldname'];
        $value = $entity->get($key);
        if (!$value instanceof \DateTime && $value !== null) {
            $value = new Carbon($value);
            $value::setToStringFormat('Y-m-d');
            $entity->set($key, $value);
        }
        parent::persist($queries, $entity);
    }

 /**
  * {@inheritdoc}
  */
 public function persist(QuerySet $queries, $entity)
 {
     $key = $this->mapping['fieldname'];
     $value = $entity->get($key);
     if (!$value instanceof \DateTime && $value !== null) {
         $value = new Carbon($value);
         $entity->set($key, $value);
     }
     parent::persist($queries, $entity);
 }