Is there a way to block out a 30 minute period before a booking?

Is there a way to stop a user booking an appointment half an hour before an appointment that already exists?

So for example, for bookings that are 30 minutes in length, if there is a booking at 10am, another user cannot book something for 9.30am as this half hour block is for the service provider to prepare for the 10am booking.

thanks,

David