Have been using this for the last year now, and it automatically leaves exactly one night free between bookings.
On the contrary however, if you choose the 2 day setting alternative: the system for some unlogical reason adds up 2 days (nights) belonging to one booking and adds on ANOTHER two days (nights) for the next booking. Which makes for a completely unpractical total of 4 nights between bookings...
I wonder why ABB seemed to think that was so useful...!
If you want an extra day between bookings now and then, you'll just have to block it manually.