Running a 90 minute countdown in the background
You can start the 90 minute timer and switch to another tab. The countdown reads the current time from your computer's clock instead of counting ticks. That means it stays accurate even when the tab is hidden or the device sleeps. The tab title shows the time left, so you can glance at it from anywhere. A running timer also survives a page reload on the same page. The end time is stored in the browser for that tab. The alarm is a browser tone, so nothing downloads. You can pick beeps, a chime, or silent with a flashing tab title. Press Space to start or pause. The display refreshes several times a second.
What people time at 90 minutes
Ninety minutes is long enough for a full block of work and short enough to stay focused. Here are common uses:
- A presentation slot with time for questions. Many conference sessions run 90 minutes.
- A long reading sprint for a textbook chapter or a set of notes.
- An exam section or a classroom activity that needs a firm stop.
- A rest between long sets at the gym, or a stretch and mobility block.
You can change the length in the duration field. Type 90m, 1h 30m, or 1:30:00. For a different preset, open the 25 minute timer or the Pomodoro timer. To count down to an exact clock time, type 9:00 or 17:30. The timer will run until that moment. If you need to measure time upward instead, the stopwatch records laps with the L key and resets with R.