The official night of midnight madness usually falls out on the students fall break. They had it in 2003, and dubbed it "Lights, Cameron, Action" (fun fact - I was in a sports marketing class at Duke at the time and I actually came up with that slogan - it was the same one that was on the poster for that year).
I just remember there was a dismal turnout for the event so I am not sure they would have it again. The Blue - White game over parents weekend is usually the official kickoff of teh Duke season for the fans i think.