CCalendar::GetOffsetUTC

static function GetOffsetUTC($userId = false, $dateTimestamp = null)
{
	if (!$userId && self::$userId)
		$userId = self::$userId;

	$tzName = self::GetUserTimezoneName($userId);
	if ($tzName)
	{
		$offset = self::GetTimezoneOffset($tzName, $dateTimestamp);
	}
	else
	{
		$offset = date("Z", $dateTimestamp) + self::GetOffset($userId);
	}
	return (int)$offset;
}