Set the alarm clock for 5:20 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 5:18 am Alarm clock for 5:19 am Alarm clock for 5:21 am Alarm clock for 5:22 am

Going to bed for a 5:20 am alarm

Asleep by 8:05 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:35 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:05 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.

5:20 am across the country

London	5:20 am
Birmingham	5:20 am
Manchester	5:20 am
Glasgow	5:20 am
Belfast	5:20 am

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

How to use the online alarm clock

As you wait for the moment to lay out the finish tokens for Saturday’s parkrun, set the alarm for 5:20 am and keep an eye on the remaining preparations. That gives you a clear cue to start arranging the funnel before volunteers and early runners arrive. With 6:00 am approaching, the alert can separate quiet waiting from the point when everything needs to move.

While you check the token sequence or gather the kit, this alarm page may slip behind another browser page. Leave its sound enabled and avoid relying on a silent visual change, as background pages can receive less attention from the browser. Treat the alarm as an on-screen aid rather than the only safeguard: if the browser session ends or the phone powers down before 5:20 am, no alert will prompt you to put out the finish tokens.

Preparing a parkrun finish area before dawn often means moving between a dim room, a lit screen and the darker outdoors. Keep the display only bright enough to read the alarm, and place it where the time is visible without repeatedly bringing it close to your eyes. Once the tokens and funnel kit are ready, turning the screen face down can reduce the glare while you wait for the sound.

Common questions

Do I need an account or an app?

Neither. Choose a time and a sound, press Start, and it runs in this browser tab. Nothing is downloaded, nothing is registered, and closing the page leaves nothing behind on the device.

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.