20 minute timer, 1,200 seconds, one third of an hour.

A 20 minute timer counts down 1,200 seconds and rings at zero. Twenty minutes is exactly one third of an hour, so three rounds make a clean hour, and two make 40 minutes. This timer has a ring that empties, soft cues at halfway and with one minute left, a label, and full screen mode. It keeps correct time in a background tab.

How to use the 20 minute timer

1. Press Start or the space bar. The countdown begins at 20:00 and the line under the numbers shows the clock time it ends.
2. Pick a label under What is it for?, or type your own in Label. It shows above the countdown, in the tab title and in the alarm notification.
3. Choose Rounds if you want the 20 minutes to repeat. A single bell marks the end of each round and the next one starts at once.
4. Pick the alarm Sound and the Volume, and press Hear the sound to check it before you start.
5. Tick a soft cue if you want one: Soft chime at halfway, Soft chime when 1 minute is left or Tick the last 10 seconds.
6. Press Pause to hold the time and Resume to carry on. +1 min adds a minute. When it rings, press Stop the alarm, or Start again to run it once more.

A twenty minute focus block

For focused work, pick Focus block, close other tabs and press Start. Twenty minutes is long enough to get through a first draft of one section or one set of problems, and short enough that the end is in sight. When it rings, decide: stop, or press Start again for another. Choosing Rounds to 3 gives you a full hour, but the bell between rounds is the only break, because the next round starts at once. If you want a rest between blocks, press Start by hand, or use the Pomodoro timer.

Out and back

For a walk or a run with a fixed route, turn on Soft chime at halfway. It plays when 10:00 is left. Turn round at that point and you arrive back near the bell. This is a pacing trick for any out and back trip, not a training plan.

Three twenties make an hour

The sums are easy: 20 + 20 + 20 = 60. With 3 rounds started at 9:00 am, the line under the numbers says the last round ends at 10:00 am. The table shows more totals.

20 minutes in other units

Nearby lengths

A twenty minute study split

For study, divide the block as 15 minutes of learning and 5 minutes of testing yourself without notes: 15 + 5 = 20. If you tick the one minute left chime, it tells you the testing part is nearly over. Use Start again for the next topic. Keep the label on Study so the tab title tells you which block you are in.

Common problems

• The ring seems slow. Over 20 minutes the ring moves a little each second, so it looks still. The numbers are exact; the ring is for a quick glance.
• You need an extra five minutes. Press +1 min five times, or type 25 in Any other time.