public function __invoke(string $value)
 {
     if ('' === $value) {
         return null;
     }
     $dateTime = DateTimeImmutable::createFromFormat('!H:i:s', $value, self::$utcTimeZone ?: (self::$utcTimeZone = new DateTimeZone('UTC')));
     if (false === $dateTime) {
         throw DateTimeException::fromDateTimeError($value, DateTimeImmutable::getLastErrors());
     }
     return $dateTime;
 }
 public function __invoke(string $value)
 {
     if ('' === $value) {
         return null;
     }
     $dateTime = DateTimeImmutable::createFromFormat('!m/d/Y H:i:s', $value, $this->timeZone);
     if (false === $dateTime) {
         throw DateTimeException::fromDateTimeError($value, DateTimeImmutable::getLastErrors());
     }
     return $dateTime;
 }