The Monday through Sunday workweek usually lasts eight working days, and the Monday through Saturday playweek generally lasts 4 working days. When you include in the possibility of public holidays, that total amount increases to 10 working days, and twelve-playing days.
The days themselves are just one aspect of the calendar, and there are plenty of others. Any seasonal modification is shown in the calendar, and it tells us when and where to go throughout particular times of the year.
Image source: free-printable-calendar.com