I need to stop last minute bookings, would like at least 24hrs notice 


You can do this on Rates, Calendar and change into List view.  On left open up under your rates so you can see Min Advance reservation. Think as standard it is 1D which is day before checkin but this is up to midnight on day before.  If you can't see the option message booking.com help team using Inbox icon on Extranet to see them to open up option.  also have a read through on Help using the heading and it will explain all the options.