Set the alarm clock for 4:31 am

Leave this tab open — the alarm only rings while the tab stays open.

The alarm goes off in: ::

You can also try the other alarm clocks

Alarm clock for 4:29 am Alarm clock for 4:30 am Alarm clock for 4:32 am Alarm clock for 4:33 am

Going to bed for a 4:31 am alarm

Asleep by 7:16 pm — 6 full sleep cycles, about 9 hours
Asleep by 8:46 pm — 5 full sleep cycles, about 7 hours
Asleep by 10:16 pm — 4 full sleep cycles, about 6 hours

A sleep cycle runs about 90 minutes, and most people take around 15 minutes to drop off. Waking at the end of a cycle feels easier than waking in the middle of one.

4:31 am across the country

Sydney	4:31 am
Brisbane	4:31 am
Adelaide	4:01 am
Perth	2:31 am
Darwin	4:01 am

Times are worked out live in your browser, so daylight saving is already accounted for.

How to use the online alarm clock

Nobody sets an alarm for 4:31 am for fun. Maybe it's an early shift at the depot, a long drive before the roads get busy, or you're still awake and don't trust yourself to notice the time. Pick a sound, set it for 4:31 am, and this page will handle the rest while the house stays quiet.

Pick whichever sound you're most likely to actually notice, then press Start. The alarm is tied to this browser tab, so it needs to stay open. Minimising the window is fine, but closing the tab or the browser will stop the countdown before it ever rings.

It's free to use, doesn't need an account, and works the same in any modern browser, but it's honestly not meant to replace your phone for anything you can't afford to sleep through. Keep the tab open and the device awake, and it'll ring reliably at the time you set. On a 24-hour clock 4:31 am is written 04:31, and spoken aloud it's twenty-nine minutes to five in the morning. Timetables and rosters may show it as 04:31, and handwritten notes as 4.31 am. Whether you would say set alarm for 4:31 am or put an alarm on for 4:31 am, the steps are the same: pick a sound, press Start, leave the tab open.

Common questions

Is this alarm accurate across daylight saving time?

It uses your device's local clock, so as long as your computer's time and date settings are correct, it'll adjust automatically when daylight saving time starts or ends.

Can I use this on my phone instead of a laptop?

Yes, it works in a mobile browser the same way, but phones are more likely to lock the screen or sleep, which can stop the alarm from ringing. A laptop or desktop tends to be more reliable for this.

Can I set more than one alarm at a time?

This page is built around a single alarm at a time. For multiple alarms, open a separate tab for each one and set a different time in each, keeping every tab open until it's rung.

Why use a browser alarm instead of my phone's built-in one?

Mainly for reliability against silent mode, do-not-disturb, or a phone left charging out of earshot. It's a useful backup or a desk-based alternative, though it depends on this tab staying open rather than running in the background of your phone.