90 Minute Timer
Set for 90 minutes. Press start — it rings when the time is up.
90:00
counting down
sound
Time’s up.
This timer runs while the tab is open. If you need it to go off when your phone is in your pocket — that part needs the app.
The ninety-minute cycle
Sleep runs in cycles of roughly ninety minutes, and the same rhythm shows up when you’re awake: attention climbs, holds, and then drops off whether you agreed to it or not.
Ninety minutes is long enough to finish something real and short enough that you can see the end from the start. What matters more than the number is the break after it — the cycle only works if it actually closes.
00:00