Running out the clock
In American football, each quarter of a game is measured with a 15-minute game clock, or 12-minute clock in many high school football codes and the German Football League. A team in possession of the lead and the ball will attempt to use up as much of the game clock as possible in order to bring the game to an end more quickly, thus denying the opposition another chance on offense.
Laws of Australian rules football
The length of a game of Australian Football can vary from league to league, but is generally around 15 to 25 minutes per quarter. In the AFL, each quarter runs for 20 minutes plus time on – which makes up for time occupied in stoppages, such as when the ball goes out of bounds, injuries, goals (or behinds) being kicked, or when the umpire is setting the angle of a free kick on goal. A typical AFL quarter might run from 27 to 33 minutes, but may be even longer if, for instance, injuries cause delays. AFL breaks after the first and third quarters are 6 minutes, with a 20-minute break at halftime. Thus, a match with quarters averaging 30 minutes would last about two and a half hours.