What is a 90 minute timer good for?
Researchers describe roughly 90-minute ultradian cycles in our alertness — which is why an hour and a half is a natural length for deep work. It's also a full football match and a common bread-proofing time.
- Ride a full 90-minute deep-focus cycle
- Track the length of a football match
- Proof bread dough for the recommended hour and a half
- Time a practice exam at full length
Frequently Asked Questions
Why 90 minutes for focus?
Studies of ultradian rhythms suggest alertness naturally rises and falls in roughly 90-minute waves — working with the wave, then resting, feels easier than fighting it.
Can I see how much time is left at a glance?
Yes — the big countdown display updates every second, and the tab keeps running in the background.