12 Minute Timer

A fifth of an hour

Twelve minutes is 720 seconds. Five runs make 60 minutes exactly and 120 runs fill a day. On a dial it is 72 degrees, one fifth of the circle, taking the minute hand from the 12 to just past the 2. Twelve sits between the two commonest blocks, ten and fifteen, and divides the hour as cleanly as either.

The NBA quarter

A period in the NBA is twelve minutes of game clock, so four quarters make 48 minutes of play. FIBA and college basketball run to 40 instead, using four ten-minute quarters or two twenty-minute halves. Real time is far longer than any of those numbers, because the clock stops constantly and this timer does not.

The Cooper run

The Cooper test is a fixed twelve-minute run scored by the distance covered rather than by time. The twelve is the whole point: change the duration and the distance stops being comparable to anyone else’s. It needs nothing but a measured track and a countdown.

Twelve as a block

Five twelve-minute blocks are an hour of work; four are 48 minutes, a full basketball game clock. Seven, eight and nine leave a remainder against the hour, so twelve is one of the few odd-sounding lengths that lines up with a schedule. The full range is on the timer page.

Before you rely on it

The timer works from the system clock, so a tab left in the background comes back with the correct number rather than a lagged one. Sound is the exception, and a sleeping phone may not fire it. Anything where a missed alarm has consequences, such as medication, an exam or a cooking step that burns, deserves a dedicated alarm instead.