@Florian-and-Theresa0 @Iske0
THanks for pointing that out, Florian! I hadn't realized that option was there!
You go to your calendar, then just above calendar on upper right is a gearwheel. Click on that, and up comes a popup box. Just below where the boxes are to fill in minimum and maximum days it says, "add a requirement for seasons or weekends." Click on that and you get another popup box where you can fill in a range of dates. Then fill in your minimum nights, and then check box where it says guests must arrive on a specific day. The difficulty you will have is that you can apparently select only ONE day of the week when you want guests to arrive on a specific day. So, like Florian is saying, you would not be able to fill in the range of dates including the whole year, because then you could only have one arrival day for the whole year. Instead, you would have to create 3 date ranges for each week of the year, in order to get Fri, Sat and Sunday, and you might only be able to do that if you had set your minimum stay as 1 day. So indeed, as Florian says, it is very complicated and might not work just as you want.