15 minute timer, a quarter hour on a clock.

A 15 minute timer counts down 900 seconds and rings at zero. Fifteen minutes is a quarter of an hour, which makes it handy for short meetings, writing sprints and anything you track in quarter hours. This timer chimes softly at halfway and with one minute left if you ask, repeats in rounds, and shows the clock time it ends. It keeps correct time in a background tab.

How to use the 15 minute timer

1. Press Start or the space bar. The countdown begins at 15:00 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 15 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 fifteen minute sprint

Pick the label Writing sprint, close everything except one document, and press Start. Write without going back to edit until the bell. The halfway chime comes when 7:30 is left: if you have less than half a page, you are being too careful, so keep going. At the bell, take one minute to note where you stopped, so the next sprint starts at once. Press +1 min to time that minute.

A fifteen minute meeting

A meeting with a fixed end tends to start with the point. Set 15 minutes, put the timer on a shared display in full screen, and agree on the agenda in the first two minutes. The one minute left chime is a polite signal to write down decisions and owners. If the topic needs more, do not stretch the bell: book a second slot with the 30 minute timer.

Quarter hours and time sheets

If you record work in quarter hours, the arithmetic is quick. Each 15 minute block is 0.25 of an hour, and four blocks are one hour. Running rounds helps you stay in the block: 3 rounds are 45 minutes, which is 0.75 of an hour. Below are the first few totals, and the end times if you begin at 9:00 am.

15 minutes in other units

Walks and breaks

A walk to the shop or round the block has a natural out and back: set the label to Walk, turn on the halfway chime, and turn back when it sounds. A lunch break works the same way. If you want the page to stay quiet in the office, set Sound to No sound and watch the tab title, or choose Chime for a soft end.

A fifteen minute agenda

Split a fifteen minute meeting as 3 minutes for context, 9 minutes for discussion and 3 minutes for decisions: 3 + 9 + 3 = 15. The halfway chime at 7:30 left lands in the middle of the discussion, and the one minute chime at 1:00 left falls in the decisions. Say the plan at the start and the room will help you keep to it.

Common problems

• The computer went to sleep. A sleeping computer cannot ring. Keep it awake for the fifteen minutes, and leave Keep the screen on ticked.
• You closed the tab by mistake. Open the page again: the timer carries on from the right time, and a click on the page lets the alarm sound again.