Set the alarm clock for 5:56 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 5:54 am Alarm clock for 5:55 am Alarm clock for 5:57 am Alarm clock for 5:58 am

Going to bed for a 5:56 am alarm

Asleep by 8:41 pm — 6 full sleep cycles, about 9 hours
Asleep by 10:11 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:41 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.

5:56 am across the country

London	5:56 am
Birmingham	5:56 am
Manchester	5:56 am
Glasgow	5:56 am
Belfast	5:56 am

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

How to use the online alarm clock

Waking at 5:56 am gives you a clear cue to get out of bed before heading to Heathrow for an early flight. You have not started the morning routine yet, so use the alarm as the point when preparation begins: sit up, check the time, and move towards the clothes and documents set aside. By 6:00 am, you can be properly under way.

While getting ready, keep this alarm page in the foreground where possible. Moving it behind another tab may leave the countdown running, but the browser can reduce activity or restrict sound when the page stays in the background. If the browser is closed or the phone falls asleep, the alarm cannot sound, so your flight morning needs a separate backup alarm. Keep the volume audible and return to this page before relying on its signal.

Before leaving for Heathrow in the early-morning darkness, avoid staring at a bright screen while checking the alarm. Lower the display brightness to a comfortable level, use the phone’s warmer night setting if available, and place it where the time remains readable without holding it close to your eyes. Once you are awake, switch on a nearby light before gathering your belongings.

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 5:56 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.