How do i alter cut off times for when guests can book the same day of check in

I’m having some issues with unscrupulous local guests wishing to book very late on the day of check in. 

They live in the suburbs 10min away but want to book my central city apartment to do there drug transactions 

how can I alter the time of that same day booking to 4pm cut off time please.

or if you have any further suggestions 

SAS4 Cathedral

I do not let same day bookings, bookings shall be made at least the night before the arrical, so I have time to prepeare the apartment.