Set the alarm clock for 7:21 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 7:19 am Alarm clock for 7:20 am Alarm clock for 7:22 am Alarm clock for 7:23 am

Going to bed for a 7:21 am alarm

Asleep by 10:06 pm — 6 full sleep cycles, about 9 hours
Asleep by 11:36 pm — 5 full sleep cycles, about 7 hours
Asleep by 1:06 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.

7:21 am across the country

London	7:21 am
Birmingham	7:21 am
Manchester	7:21 am
Glasgow	7:21 am
Belfast	7:21 am

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

How to use the online alarm clock

If you’re preparing ahead for the first train to London, set the 7:21 am alarm while there is still time to check your route, ticket and journey to the station. That leaves 39 minutes before 8:00 am, giving you room to spot a wrong setting without turning the morning into a rush.

While your travel plans are still flexible, choose the alarm sound and run a brief test at the same volume you intend to use. Confirm that it is clearly audible from where you will sleep, rather than assuming the current media volume is suitable. Keep the browser running and the phone or computer awake overnight: otherwise, the alarm may stay silent and the first train could leave without you.

Because a 7:21 am alarm can reach beyond your bedroom, think about anyone else sleeping in the house before raising the volume. Place the phone close enough for a moderate signal to wake you, and use vibration on a stable bedside surface if that helps. Once awake, silence it promptly and keep clothes, keys and your rail ticket together so early movement around the house causes less disturbance.

Common questions

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.

What happens if my laptop goes to sleep before 7:21 am?

The tab sleeps along with it and the alarm will not sound on time, if at all. If you are relying on it, change the power settings so the machine stays awake, or keep a phone alarm running as well.

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.