Actually, if you double book the CM's may cancel both reservations. WHen I called to make reservations for my June trip I changed a Brown Derby lunch from 1pm to 11:30. The CM I talked to forgot/or didn't completely cancel the 1:00 so it looked as if I was double booked. Thankfully I called later and found out when the CM said my number had been highlighted because I was double booked and my reservations were going to be cancelled! I don't know if it was because it was at the same restaurant of what but I wouldn't do it.