Turn off Add a night

[Jacquie51]

I only want weekly bookings because I have a vacation home.  I specified 7 night minimal stay and I can specify which days to allow check-ins, only Saturdays.  However, when I look at my listing, I noticed a "Add a night" feature which allows them to stay Sat-Sun and disrupts the next weeks booking.  How do I turn that feature off or only allow checkouts on Sunday