Set the alarm clock for 4:02 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 4:00 am Alarm clock for 4:01 am Alarm clock for 4:03 am Alarm clock for 4:04 am

Going to bed for a 4:02 am alarm

Asleep by 6:47 pm — 6 full sleep cycles, about 9 hours
Asleep by 8:17 pm — 5 full sleep cycles, about 7 hours
Asleep by 9:47 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.

4:02 am across the country

London	4:02 am
Birmingham	4:02 am
Manchester	4:02 am
Glasgow	4:02 am
Belfast	4:02 am

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

How to use the online alarm clock

Preparing at 4:02 am for a solstice sunrise at Stonehenge gives you time to check your layers, pack a flask and gather anything needed for the early journey. The 58 minutes before 5:00 am can cover those final preparations without turning the morning into a rush. Set the alarm for the moment you need to move from planning to leaving.

Your Stonehenge sunrise depends on hearing the signal, so check the phone or laptop’s sound settings before relying on it. Silent mode may prevent the chosen tone from being audible even when the on-screen alarm is running. Raise the volume and play a brief sample if one is available. The sunrise plan will have no alarm behind it if you close the browser page or allow the phone or laptop to fall asleep.

While preparing in the dark, a bright screen can feel harsh against the surrounding night. Lower its brightness before entering the time, and use a warmer display setting if your phone or laptop provides one. Once 4:02 am is set, place the screen face down or angle it away so its glow does not dominate the room, while keeping the equipment awake and connected to power.

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 4:02 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.