Timing · game clock, play clock and overtime
American football game clock: quarters, play clock, timeouts and overtime
A practical guide to regulation time, the game clock and play clock, the two-minute stoppage and the major NFL/NCAA overtime differences.
Four quarters and the game clock
Regulation play is divided into four 15-minute quarters. The game clock does not run continuously: it stops for specific events such as scores, timeouts and certain incomplete-pass or out-of-bounds situations, then restarts according to the competition’s timing rules.
The play clock: 40 seconds and 25 seconds
A separate play clock limits how long the offense has to start the next play. NFL and NCAA football commonly use a 40-second clock after the previous play and a 25-second clock after designated administrative stoppages. If the offense does not snap before it expires, delay of game can be called.
The final two minutes
Late in each half, timing becomes more restrictive. The NFL uses a two-minute warning; NCAA football uses an automatic two-minute timeout. Rules for first downs, out-of-bounds plays, penalties and clock runoffs can change in this period, so the exact competition rule matters.
Overtime is not the same in NFL and NCAA
In the NFL regular season, overtime is one 10-minute period and both teams normally get an opportunity to possess the ball; the game can still end tied when time expires. NCAA overtime uses alternating possessions rather than a timed extra quarter, with each team starting a possession at the opponent’s 25-yard line; from the third overtime, teams alternate two-point conversion attempts.