I work in a school, the school runs a number of clubs. These clubs are booked online during a booking window of around two weeks. I am trying to write a sign to let parents know that the booking window will close at a certain time but am struggling with the exact grammar. To clarify there are multiple clubs, each club will have multiple bookings and each parent may make multiple bookings at multiple clubs.
Should it be (and why):
Club booking closes tonight at 10pm
Clubs booking closes tonight at 10pm
Club bookings close tonight at 10pm
Clubs bookings close tonight at 10pm