Set the alarm clock for 5:12 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 5:10 am Alarm clock for 5:11 am Alarm clock for 5:13 am Alarm clock for 5:14 am

Going to bed for a 5:12 am alarm

Asleep by 7:57 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:27 pm — 5 full sleep cycles, about 7 hours
Asleep by 10:57 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.

5:12 am across the country

London	5:12 am
Birmingham	5:12 am
Manchester	5:12 am
Glasgow	5:12 am
Belfast	5:12 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 are finishing another task, a 5:12 am alarm marks the moment to break away and head for a parking space at the station. That leaves a useful stretch before 6:00 am for getting outside, starting the car and reaching the commuter car park before the usual weekday flow builds.

Because this alarm is meant to interrupt what you are doing, its sound needs checking beforehand rather than at 5:12 am. A phone left on silent may give only a visual alert, so set a suitable volume and try a brief test while preparing. Do not rely on it as the only safeguard for your station parking space: the alarm cannot sound after its browser page is closed or the phone has fallen asleep.

A pre-dawn trip to the station is easier with something simple already prepared. Water and a light snack are practical before leaving, especially if breakfast usually happens later at home or near work. A large meal can wait until after the drive, avoiding extra preparation when the aim is to leave promptly. Keep the drink in a secure holder and any food packed away until the car is parked.

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 5:12 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.