CCrmDateTimeHelper::getUserTime

static function getUserTime(DateTime $serverTime, int $userId = null, bool $isForced = false): DateTime
{
	$offset = $isForced
		? CTimeZone::GetOffset($userId, true)
		: self::getUserTimezoneOffset($userId);

	$time = clone $serverTime;
	if ($offset)
	{
		$time->add(($offset < 0 ? '-' : '') . 'PT' . abs($offset) . 'S');
	}

	return $time;
}