Set the alarm clock for 5:17 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 5:15 am Alarm clock for 5:16 am Alarm clock for 5:18 am Alarm clock for 5:19 am

Going to bed for a 5:17 am alarm

Asleep by 8:02 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:32 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:02 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.

5:17 am across the country

London	5:17 am
Birmingham	5:17 am
Manchester	5:17 am
Glasgow	5:17 am
Belfast	5:17 am

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

How to use the online alarm clock

While you keep an eye on the clock before preparing a full breakfast for your guests, set the alarm for 5:17 am so the kitchen work begins at the intended moment. That leaves a useful stretch before 6:00 am for heating the grill, filling the kettle and laying out plates without rushing the first cooked items.

A breakfast kitchen can already be noisy, so choose a signal volume that remains clear above the extractor fan, running water and clatter from pans. Test it from the furthest worktop rather than beside the phone, and keep the sound source away from folded tea towels or cupboards that may muffle it. The breakfast alarm cannot sound if the browser is no longer running or the computer has gone to sleep, so keep the setup active until 5:17 am and use a separate backup if missing the cue would delay guests.

Before the guesthouse begins stirring, early darkness can make labels, switches and utensils harder to distinguish at a glance. Leave a low kitchen light on, or position a lamp to illuminate the preparation area before waiting for 5:17 am. Avoid facing a harsh bulb towards the doorway; gentle, directed light helps you move between the kettle, hob and serving space without lighting every room.

Common questions

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.

What happens if my laptop goes to sleep before 5:17 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.