20 MINUTES TIMER
20:00
Presets
You've reached the 20 minutes timer from AlarmClock24. The widget above is preloaded with 20 minutes. Press "Start" and the countdown begins.
What is a 20 minutes timer good for?
20 minutes is the length of the coffee nap. Drink a coffee, set the 20-minute timer, nap, and when it rings the caffeine will be starting to take effect. The favorite technique of night shifts and students.
Practical tip
The coffee nap works because caffeine takes ~20 minutes to kick in. If you sleep more than 20 minutes you enter deep sleep and wake up worse.
Frequently asked questions
Does the timer keep running if I switch tabs?
Yes, the timer keeps running even if you switch tabs or minimize the browser. It uses absolute timestamps so the countdown stays accurate even if the tab loses focus.
Can I make the timer repeat automatically?
Yes, enable the "Repeat when finished" option in the timer widget. When it rings, the countdown starts over automatically. Useful for interval exercises or periodic reminders.
Does the coffee nap really work?
Yes, it has scientific backing. Adenosine (the substance that produces sleepiness) decreases during light sleep, and caffeine blocks the remaining adenosine receptors. Timing is key: exactly 20 minutes. If you sleep longer, you enter deep sleep and the effect is lost.