public static function now(?string $timezone = null): Time
    {
        $timezone = $timezone ?: date_default_timezone_get();
        assert(Validate::isTimezone($timezone), sprintf('Invalid timezone: %s', $timezone));

        $dateTime = new DateTimeImmutable('now', new DateTimeZone($timezone));
        $hour = (int) $dateTime->format('G');
        $minute = (int) $dateTime->format('i');
        $second = (int) $dateTime->format('s');

        return new static($hour, $minute, $second);
    }