Set the alarm clock for 5:48 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 5:46 am Alarm clock for 5:47 am Alarm clock for 5:49 am Alarm clock for 5:50 am

Going to bed for a 5:48 am alarm

Asleep by 8:33 pm — 6 full sleep cycles, about 9 hours
Asleep by 10:03 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:33 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.

5:48 am across the country

London	5:48 am
Birmingham	5:48 am
Manchester	5:48 am
Glasgow	5:48 am
Belfast	5:48 am

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

How to use the online alarm clock

You are only just waking at 5:48 am, with the Saturday parkrun finish tokens still waiting to be laid out. The alarm marks the moment to get upright, gather what you need and leave enough breathing room before the morning setup begins. By 6:00 am, you can be dressed and moving rather than trying to make decisions while half awake.

For this particular start, the useful check happens well before Saturday morning: set a temporary alarm while you are already awake, keep the sound level where you expect it, and listen for the actual signal. That small rehearsal confirms that the selected tone is audible and recognisable. If the browser is dismissed or the phone goes to sleep, however, no sound may arrive, leaving the parkrun finish tokens untouched when you meant to set off.

An early alarm can protect the sleep left before 5:48 am if the practical details are settled the night before. Put the finish tokens, keys and outdoor layer together, then choose a single alarm rather than several closely spaced ones. When it sounds, there is less reason to switch on a bright light or search through drawers, so the remaining night stays quiet right up to the planned waking time.

Common questions

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 5:48 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.