Each quarter of an NBA basketball game is 12 minutes, though the time to complete any given quarter varies. The game clock stops for team timeouts, television timeouts, player fouls and when the ball leaves the court of play (out-of-bounds), prolonging the actual time it takes to complete each quarter.
There is a 130-second intermission between the second and third quarters and third and fourth quarters. The halftime intermission, following the second quarter of play, lasts 15 minutes. Per league rules, the public address operator is required to announce when exactly two minutes remain in each quarter. In the final minute of each period, the official game clock must include tenths of a second. Games tied at the end of regulation play additional five-minute overtime periods, until a winner is determined. The average non-overtime NBA game lasts 2 hours, 15 minutes, according to the Elias Sports Bureau. There is a 130-second intermission between the second and third quarters and third and fourth quarters.