public function utcIsoToTimestamp($isoTime)
    {
        $utcTimeZone = new \DateTimeZone('UTC');
        $dateTime = \DateTime::createFromFormat(self::SOLR_ISO_DATETIME_FORMAT,
            $isoTime, $utcTimeZone);
        return $dateTime ? (int)$dateTime->format('U') : 0;
    }
public function utcIsoToTimestamp($isoTime)
    {
        $utcTimeZone = new \DateTimeZone('UTC');
        $dateTime = \DateTime::createFromFormat(self::SOLR_ISO_DATETIME_FORMAT,
            $isoTime, $utcTimeZone);
        return $dateTime ? (int)$dateTime->format('U') : 0;
    }
public function utcIsoToTimestamp ( $ isoTime ) { $ utcTimeZone = new \ DateTimeZone ( 'UTC' ) ; $ dateTime = \ DateTime :: createFromFormat ( self :: SOLR_ISO_DATETIME_FORMAT , $ isoTime , $ utcTimeZone ) ; return $ dateTime ? ( int ) $ dateTime -> format ( 'U' ) : 0 ; }
Converts a date from ISO 8601 format in UTC timezone to unix timestamp.

@param string $isoTime date in ISO 8601 format
@return int unix timestamp
Converts a date from ISO 8601 format in UTC timezone to unix timestamp .