/**
  * {@inheritdoc}
  */
 public function convertToDatabaseValue($value, AbstractPlatform $platform)
 {
     if ($value === null) {
         return null;
     }
     $value->setTimeZone(self::$utc ? self::$utc : (self::$utc = new \DateTimeZone('UTC')));
     return parent::convertToDatabaseValue($value, $platform);
 }