PHP timezone conversion functions

gistfile1.aw

/**
 * Get the offset of the given timezone (in seconds)
 */
function getTimeZoneOffset($timezone='') {
	$tz_tmp = new DateTimeZone($timezone);
	$dt_tmp = new DateTime('now', $tz_tmp);
	$offset = $dt_tmp->getOffset();
	return $offset;
}

/**
 * Convert the given time from the origin time zone to the destination time zone
 */
function convertTime($datetime='0000-00-00 00:00:00', $origin_timezone='GMT', $destination_timezone='GMT', $output_as_mysql=false) {
	$time = $datetime;
	if (!is_int($time)) {
		$time = strtotime($datetime);
	}
	$originOffset = $this->getTimeZoneOffset($origin_timezone);
	$destinationOffset = $this->getTimeZoneOffset($destination_timezone);
	$gmtTime = $time - $originOffset;
	$convertedTime = $gmtTime + $destinationOffset;
	if ($output_as_mysql) {
		$convertedTime = date('Y-m-d H:i:s', $convertedTime);
	}
	return $convertedTime;
}