Set the alarm clock for 9:21 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 9:19 am Alarm clock for 9:20 am Alarm clock for 9:22 am Alarm clock for 9:23 am

Going to bed for a 9:21 am alarm

Asleep by 12:06 am — 6 full sleep cycles, about 9 hours
Asleep by 1:36 am — 5 full sleep cycles, about 7 hours
Asleep by 3:06 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.

9:21 am across the country

London	9:21 am
Birmingham	9:21 am
Manchester	9:21 am
Glasgow	9:21 am
Belfast	9:21 am

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

How to use the online alarm clock

You have just woken up and need to appear at a magistrates’ court, so set the alarm for 9:21 am before getting out of bed. That gives you a clear point for starting the morning rather than drifting through washing, dressing and gathering your papers. With 10:00 am approaching, check the hearing location and planned journey before deciding how long each task can take.

Your court appearance depends on hearing the alert, so leave this browser alarm somewhere it can remain active and audible. A computer or phone that goes to sleep before the set time may silence your magistrates’ court reminder, leaving you without the warning you expected. Keep the sound turned up, avoid power-saving settings that suspend the browser, and use a separate phone alarm if missing 9:21 am could make you late.

Once the court journey is mapped out, work backwards from the time you must leave rather than treating 9:21 am as the only deadline. Allow a morning buffer for security checks, finding the correct entrance and any public-transport delay. Also note what follows the hearing later today: protecting enough time before that next commitment keeps one slow queue or longer session from disrupting the rest of your plans.

Common questions

Can I change the sound?

Yes, there is a short list of tones to pick from before you press Start. Softer sounds are easy to sleep through, so a firmer bell tends to be the safer choice for anything early in the morning.

Will it still be right when the clocks change?

Yes. It reads your device's local clock, so the move between GMT and BST at the end of March and October is picked up automatically, as long as the computer's date, time and time zone are set correctly.

Can I use this on a phone?

It works in a mobile browser, but phones lock the screen and suspend background tabs far more readily than a laptop does, which can stop the alarm sounding. For anything important, a desktop or a plugged-in laptop is the steadier option.

Does the alarm still work if I close the tab?

No. Everything runs inside this page, so closing the tab — or quitting the browser altogether — ends the countdown there and then. Leaving it open in the background is all it asks, and switching to another tab makes no difference.