When playing Nazi Zombies, particularly on Der Riese, "Obama Time" is what you say when someone asks "Who is going to open the door? Obama Time is in reference to the person with the most points at the time, therefore punishing that person for doing well much like Obama is doing to everyday people.
Player 1: Come on we need to open the door to the teleporter!
Player 2, 3, and 4: Obama Time
Player 1: damnit, this is BS