If I may interject on the subject of reservation times, a situation which can often arise is that a restaurant will become fully booked on a first come-first served basis and give people a reservation for their preferred time. After that, rather than turn away business and disappoint people, they may re-book the tables that were previously reserved for say 9pm and inform people that they need the table back. If there is strong demand for reservations, it is very difficult to accommodate everyone so I think a system of accomodating those who reserve first and then offering early or late tables to diners who book nearer to the day, is about as fair as one can be.