Set the alarm clock for 4:39 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 4:37 am Alarm clock for 4:38 am Alarm clock for 4:40 am Alarm clock for 4:41 am

Going to bed for a 4:39 am alarm

Asleep by 7:24 pm — 6 full sleep cycles, about 9 hours
Asleep by 8:54 pm — 5 full sleep cycles, about 7 hours
Asleep by 10:24 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.

4:39 am across the country

London	4:39 am
Birmingham	4:39 am
Manchester	4:39 am
Glasgow	4:39 am
Belfast	4:39 am

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

How to use the online alarm clock

With the final drinks served, you are finishing the bar close and preparing to leave at 4:39 am. Set the alarm for this exact time if it marks your last check of the tills, doors or lights. With 5:00 am approaching, it can also separate the remaining closing jobs from the moment you need to head home.

Before beginning the bar lock-up, test the signal while you can still hear it and change the volume if needed. A short trial confirms that the chosen sound is noticeable above cleaning noise and that your phone is not muted. For the bar close, keep the alarm running on an awake phone until it sounds; leaving the page or allowing the phone to sleep may silence it, so it should not be the only reminder tied to your departure.

As you finish under dim lighting, reduce the screen brightness enough to avoid a harsh glare without making the controls difficult to read. Check that 4:39 am is displayed correctly, then place the phone where the screen will not reflect directly into your eyes. Once the alarm is set, leaving the display alone can make the final few minutes of paperwork or door checks less visually tiring.

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.