I just emailed Dima this suggestion for the Booking Calendar plugin:
It would be great if there was an option to lock the calendar so that the user can only book complete weeks and the option to set start day. Lets say the users can only book complete weeks going from saturday-friday.
I'm making a booking page for a house which can only be rented by the week. Many house rental agencies work like that. And I'm sure there must be more use for this feature.
Please write something here if you too need that feature so that Dima will incorporate that feature in an upcomming release.