One other question, when does the event get over?
Though Norm's answer is generally correct, there are other factors that determine when we end game. These factors can depend on the site and our reservation, as well as our staff's schedule. If our GM has to be at work by 16:00 on Sunday, we usually end game at 10 or 10:30, and try to be off site by 13:00 (for example).
How's that looking for this weekend?