What fits in 20 minutes
- The NASA-adjacent nap — restorative, pre-grogginess.
- 20-20-20 eye breaks for screen marathons.
- Bake salmon, roast asparagus, simmer rice.
- One focused writing block — about 300 rough words.
Twenty minutes and the attention curve
Lecture research keeps finding attention sagging somewhere past the 15–20 minute mark — the reason TED talks cap at 18. Use that curve deliberately: teach, present, or study in 20-minute segments with a state change between them (stand, question, switch mode), and retention holds where a 60-minute slab would slump.
How this timer works
Press Start and the countdown anchors to your device's clock, so it stays second-accurate even in a background tab — the time remaining also ticks in the tab title. When it hits zero the display flashes and an alarm beeps three rounds (toggle the sound off if you prefer a silent flash). Use +1 min to extend on the fly, and fullscreen for a wall-visible display in classrooms and gyms.
Frequently asked questions
Why 20 minutes for the 20-20-20 eye rule?
Optometrists suggest that every 20 minutes of screen work, you look at something 20 feet away for 20 seconds to relax eye-focusing muscles. Loop this timer during long sessions as the reminder.
Is a 20 minute nap better than 15?
NASA's famous flight-crew study used naps averaging ~26 minutes; 20 is a practical civilian target — more restorative than 15 for most people while still dodging deep-sleep inertia.
Will the timer keep running if I switch tabs?
Yes — the countdown is anchored to your device clock, not to the page being visible, so it stays accurate in a background tab. The remaining time also shows in the tab title so you can see it at a glance.
Does the alarm work with my phone on silent?
The alarm plays through the browser at your media volume. If your device is muted or the tab's sound is blocked, you'll still see the display flash and the tab title change — but for must-not-miss timing, unmute or keep the tab visible.