@Lawrence21 , I confirm! it just got messed up here in the thread a bit because some people are confusing the confirmation email we get from Airbnb, where it lists check in and check out day just like a hotel does - with the actual nights spent and paid for, which is what your clendar and your payments reflect. So if it says in the confirmation email that check in is friday... check out is Sunday, then the guest is only staying and paying for two nights, Friday and Saturday. Simple enough, your blocked out calendar days for a specific guest will confirm this. Any day that is available on you calendar is a day a guest pays for, the checkout date is the following day.
It might get a little tight if you have a late check out time and early check in time. then, if you have someone arriving on the check out date of the previous guest, you might have to scramble to clean up in between. For that reason, I don't allow same day bookings and I also have one day before and after a stay blocked out in my booking settings. gives me peace of mind.