Set the alarm clock for 11:51 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 11:49 am Alarm clock for 11:50 am Alarm clock for 11:52 am Alarm clock for 11:53 am

Going to bed for a 11:51 am alarm

Asleep by 2:36 am — 6 full sleep cycles, about 9 hours
Asleep by 4:06 am — 5 full sleep cycles, about 7 hours
Asleep by 5:36 am — 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.

11:51 am across the country

Sydney	11:51 am
Brisbane	11:51 am
Adelaide	11:21 am
Perth	9:51 am
Darwin	11:21 am

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

How to use the online alarm clock

A quick nap over lunch only works if something reliably wakes you up again, and 11:51 am is a common target for exactly that. Set the time, pick a tone, and this tool will ring at 11:51 am through your speakers so the rest of your day isn't wrecked.

Set your preferred sound, press Start, then leave the tab where it is. Everything happens inside the browser — no background app, no notification pushed from a server — so an open tab is what actually makes the alarm ring at the right time.

A browser alarm like this one is handy when your phone's on silent, charging in another room, or you just don't want to unlock it and get pulled into notifications. The trade-off is honesty: it only rings while this tab stays open, so it's not a replacement for your phone alarm on a trip where the laptop lid might close. On a 24-hour clock 11:51 am is written 11:51, and spoken aloud it's nine minutes to twelve in the afternoon. You'll also see it written 11.51 am — a full stop instead of the colon means the same time. Set an alarm for 11:51 am, set the alarm to 11:51 am, set my alarm for 11:51 am — all of it lands on this page and does the same thing.

Common questions

What happens once the alarm goes off?

It rings through your device's speakers on a loop until you stop it from this page. There's no separate app notification, so make sure your volume is turned up before you rely on it.

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.