public function convertToUTC($timestamp, $timezone, $format = 'Y-m-d H:i:s')
    {
    	$date = new DateTime($timestamp, new DateTimeZone($timezone));

        $date->setTimezone(new DateTimeZone('UTC'));

        return $date->format($format);
    }
public function convertToUTC($timestamp, $timezone, $format = 'Y-m-d H:i:s')
    {
    	$date = new DateTime($timestamp, new DateTimeZone($timezone));

        $date->setTimezone(new DateTimeZone('UTC'));

        return $date->format($format);
    }
@param integer $timestamp
@param string $timezone
@param string $format

@return string