Actually, there isn't. Disney's attendance is rather constant. While it varies from month to month, overall, the trends stay constant. If 100,000 people are going to be staying on or near the property on February 1, it doesn't really matter if those 100,000 people get up at 6:00 a.m. to fight for their ADRs 60 days ahead of that, 90 days ahead, or 180 days ahead of that. There is no advantage to any particular person irrespective of which arbitrary cutoff you use. As for the restaurant itself, one could make the argument that for staffing and supplying purposes, the establishment will wnat to know as early as possible what their bookings look like so that they can prepare. But at WDW, the restuarant knows that it is going to be booked to capacity on any given night. It just doesn't know the names of those diners, nor does it need to. Disney Dining worked just fine for decades with a 60 day system, and for years with a 90 day system. There is no improvement with a 180 day system. Indeed, I think that they are hurting themselves. How many people with "last minute" opportunities to go to WDW (meaning 90 days out or less) will skip the chance because they know that they cannot eat any place meaningful? As I see it, the 180 day system actually discourages certain people from filling up hotel rooms that otherwise might have been enticed to go.