code: public function decode($value, Field $field, Codec $codec = null)
      {
          if (empty($value)) {
              return null;
          }
  
          if ($value instanceof \DateTimeInterface) {
              return $this->convertToUtc($value);
          }
  
          $date = \DateTimeImmutable::createFromFormat(DateUtils::ISO8601_ZULU, str_replace('+00:00', 'Z', $value));
          if ($date instanceof \DateTimeInterface) {
              return $this->convertToUtc($date);
          }
  
          throw new DecodeValueFailed(
              $value,
              $field,
              sprintf(
                  'Format must be [%s].  Errors: [%s]',
                  DateUtils::ISO8601_ZULU,
                  // this is mutant
                  print_r(\DateTimeImmutable::getLastErrors() ?: \DateTime::getLastErrors(), true)
              )
          );
      }
docs: {@inheritdoc}