The Monday through Sunday workweek typically lasts 8 working days, and the Monday through Saturday playweek typically lasts four working days. When you add in the possibility of public holidays, that overall amount increases to ten working days, and twelve-playing days.
However the days themselves are just one element of the calendar, and there are a lot of others. The months of the calendar represent different seasons, and the time between each of those months offers us the seasonal cycle. At the start of spring, the temperature level is high and the days are warm, while at the end of winter season the air is cold and the days are chilly. Every season has its own unique time connected with it, and the calendar helps us keep an eye on all of those shifts. Any seasonal change is reflected in the calendar, and it informs us when and where to go during particular times of the year.
Image source: calendarzoom.com