20 Minute Timer
Twenty minutes, with an alarm at the end. The upper limit of a good nap, a full meditation session, and the interval most eye-strain advice is built around.
Counting down
20:00
Twenty minutes
Twenty minutes is a ceiling rather than a target in most of its uses, which makes it unusual. A nap should not go past it. A screen stretch should not go past it. In both cases the timer exists to stop something rather than to fill it.
The nap case is the clearest. Sleep runs in cycles, and the first twenty minutes or so are light. Wake inside that window and you get the alertness without the fog; wake after it and you are surfacing from deep sleep, which produces the grogginess that makes people say naps do not work for them. The difference between a good nap and a bad one is often ten minutes.
The screen case is the 20-20-20 rule, which is the standard advice for eye strain: every twenty minutes, look at something twenty feet away for twenty seconds. The reason it works is that the muscle holding your eyes focused at desk distance is doing continuous static work, and it is the only muscle in your body you would never think to rest.
Used as a work block it sits in an awkward middle — longer than a drill, shorter than the twenty-five that the pomodoro settled on, and much shorter than what reading or writing wants. Where it does earn its place is as a hard stop on something open-ended: twenty minutes on the inbox, on the washing up, on a problem you have been circling.
What people use it for
- A nap, kept under the deep-sleep threshold
- Meditation once ten minutes is comfortable
- The 20-20-20 screen break interval
- A hard stop on an open-ended chore
- Oven and slow-cooking stages
How it works
Set to twenty minutes already — Start or Space.
The alarm is scheduled the moment you press start, on the audio clock rather than a JavaScript timer, which is what makes it usable for a nap. A timer that only fires when the tab wakes up is exactly the wrong kind for the one job where you are not watching.
The screen is held awake while it runs and released as soon as it stops or you pause.
Any other length works — change the minutes, or add seconds.
- Space
- Start or pause.
- R
- Reset.
- Tab title
- Shows the time left, so a background tab still tells you.
Questions
Is twenty minutes too long for a nap?
It is the usual upper limit. Ten to twenty minutes keeps you in light sleep, so you wake alert. Past about twenty-five you start entering deep sleep, and waking out of that is what causes the grogginess.
What is the 20-20-20 rule?
Every twenty minutes of screen work, look at something about twenty feet away for twenty seconds. It rests the focusing muscle in the eye, which is otherwise held in one position for hours.
Will the alarm definitely go off?
It is scheduled in advance on the audio clock, which is independent of the throttled JavaScript timers a background tab gets. For a nap, allow notifications too so there are two separate signals.
Can I set it to repeat every twenty minutes?
Not on this page. The interval timer will run any number of repeating blocks back to back, which is the better tool for a screen-break cycle.
Is twenty minutes long enough to meditate?
It is a common length for an established practice, and roughly what the transcendental meditation tradition prescribes twice a day. Ten is the usual starting point.
Does it stay accurate if I leave the page in the background?
Yes. It works out the remaining time from the clock every repaint rather than accumulating ticks, so throttling has no effect on when it finishes.
Can I change it to 25 minutes?
Yes, though at twenty-five you probably want the pomodoro timer, which runs the break afterwards for you rather than stopping dead.