90 Minute Timer
One full sleep cycle, or one long block.
90 Minute Timer ready. Press start to begin.
Each mark is five minutes
Ninety minutes is the length of a sleep cycle and, not coincidentally, about as long as focused attention holds before it needs a real rest. It is the longest block most people can work in without the last third going to waste.
What 90 minutes is good for
A deep-work block
The long end of useful focus. Anything past this is usually recoverable only with a proper break.
A full nap cycle
Ninety minutes wakes you at the end of a cycle rather than the middle of one.
A film, a match, a class
The length a surprising amount of the world is organised around.
Questions
Why ninety minutes?
Human alertness moves in cycles of roughly ninety minutes, awake and asleep. Working with that rhythm rather than against it is why the block tends to end at a natural stopping point.
Is it a good nap length?
It is the long option. Fifteen to twenty minutes keeps you out of deep sleep; ninety takes you through a full cycle and back out. Between the two is where people wake up feeling worse.
Will it make a sound when it finishes?
Yes — an alarm rings when the countdown reaches zero. The countdown also turns red and the tab title changes to "Time's up", so the end is visible as well as audible.
Does the timer keep running if I switch tabs?
Yes. The countdown runs from a real timestamp rather than counting frames, so it stays accurate in a background tab, and the remaining time shows in the tab title.
The hard part isn’t the timer
This page counts down, and that is all it does. Porotimer handles the part that decides whether the session actually works.
Lock away what breaks focus
Choose the apps you're allowed for the session. Porotimer puts everything else behind a wall until the timer ends — which is the one thing a page in a browser tab can never do.
Learn more
Breaks that actually rest you
A calm scene and a breathing guide when the sprint ends, instead of five minutes of scrolling. You come back settled rather than scattered.
Learn more
See where the hours went
Every sprint and break laid out in order. The day becomes something you can look back on, rather than something you try to remember.
Learn more