code: public function convertDateTimeToUtcTimeZone($inStrictIso8601DtTm)
      {
          $tmpDateTimeIn = $this->convertTimeFromFormatSafely($inStrictIso8601DtTm);
          $tmpDateTimeIn->setTimezone(new \DateTimeZone('UTC'));
          return $tmpDateTimeIn->format('Y-m-d H:i:s');
      }
docs: Converts a Date from ISO-8601 format into UTC Time zone SQL format
  
  @param string $inStrictIso8601DtTm
  @return string