How do midnight launches work?

Exactly when does gamestop open their doors?

and even if they open the doors pre midnight does that mean you can leave with your copy BEFORE midnight?

I been discussing it with a guy on gamespot he said they should open around 10:30 or 11:00 , and then ring everyone up ahead of time and then when its midnight give everyone their game

they also said they should stay open untill about 1:00AM

Do any of you know any specifics?