Bookings
The waitlist
When you are full, guests leave their details; a cancellation fills the table.
When a day is fully booked, guests can join the waitlist with the times they could come. When a table becomes free, everyone waiting for that time gets an e-mail at once, and the first to book gets the table.
You see the waitlist under the day's bookings and can e-mail the guests yourself or remove an entry.