“The panel indicates when the indication on the road sign applies. If times are used in combination with other conditions, the panel also indicates when these conditions apply. Black or white figures without brackets indicate weekdays, except weekdays before Sundays or public holidays. Black or white figures within brackets indicate weekdays before Sundays or public holidays. Red figures indicate Sundays or public holidays. If the time limit extends past midnight, it applies after midnight the following day. If a certain day or certain weekday is indicated, the regulation applies to this day regardless of whether the day is a weekday, Sunday or public holiday.” (Traffic Sign Ordinance)
According to the law, a regular Saturday is a weekday. A week without any public holidays contains 6 weekdays: Monday–Saturday.