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

@param string $inStrictIso8601DtTm
@return string