Pillow Math

Set alarm for 3:10 AM

Nobody sets an alarm for 3:10 AM because they want to; it is a night shift, a flight, a feed, or a call across too many time zones, and I have set it for every one of those. The first beeps are soft on purpose, so a sleeping house stays asleep while you do not. If you can afford a few more minutes, 3:25 AM has its own page.

Rings at

3:10 AM

How this alarm works

This page is the alarm from the online alarm clock with the time already filled in: 3:10 AM. Press Set alarm and it counts down to the next time the clock shows 3:10 AM, tonight or tomorrow, whichever comes first. When it rings, the sound starts quiet and gets louder over a minute, a notification goes up if you let the browser send one, and if you tick the math box it will not stop until you type the right answer to something like 23 + 41. Snooze does not need the answer.

If 3:10 AM is when you have to be up, the harder question is when to turn the light off. I count back in sleep cycles, and the sleep calculator does that arithmetic for you: enter 3:10 AM as the wake time and it gives you four bedtimes that end a cycle right at the alarm. I wrote up the research behind the numbers in what time should I go to bed.

What it cannot do

It rings while this page is open, in a tab or as the installed app; a locked phone is not guaranteed, because there is no server that can wake it from outside. That gap is one reason I am building a real alarm app for heavy sleepers, and until it is ready I set the phone's own alarm as well and use this one at a desk.

Questions I get about this

Does the 3:10 AM alarm ring if I close the tab?
No. The alarm is JavaScript running in this page, so it rings while the page is open, in a background tab on a laptop or desktop, or as the installed app. Close the tab and there is nothing left to ring. If the morning matters, set your phone's alarm for 3:10 AM as well and keep this one as the backup that makes you do arithmetic.
How do I install it?
Open the browser menu and choose Add to Home Screen or Install. You get an icon that opens straight to the alarm without the browser around it, and the last version you loaded keeps working without a network. It is still a web page underneath, with the same limits, so a locked phone is not guaranteed to ring at 3:10 AM.
I need to be up at 3:10 AM. When should I be asleep?
Count back from 3:10 AM in sleep cycles of roughly 90 minutes. Six cycles is nine hours, five is seven and a half, and both sit inside the 7 to 9 hours the National Sleep Foundation panel recommends for adults. The sleep calculator does that arithmetic and adds the minutes it takes you to fall asleep.
Does it repeat every day?
No. Once it has rung and you have stopped it, it is done. If you come back to this page tomorrow with the tab still open it will still be set for 3:10 AM, and if the tab was closed while it was due, the page tells you it went off without you and sets it again for the next 3:10 AM.

Everything on Waking up

What to sleep on

Guides to pillows, built from the manufacturers' own specifications and the arithmetic this site runs on. Nobody here has slept on these.

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