Set the alarm clock for 10:33 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 10:31 am Alarm clock for 10:32 am Alarm clock for 10:34 am Alarm clock for 10:35 am

Going to bed for a 10:33 am alarm

Asleep by 1:18 am — 6 full sleep cycles, about 9 hours
Asleep by 2:48 am — 5 full sleep cycles, about 7 hours
Asleep by 4:18 am — 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.

10:33 am across the country

London	10:33 am
Birmingham	10:33 am
Manchester	10:33 am
Glasgow	10:33 am
Belfast	10:33 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 watching the clock for the moment to collect a prescription from your GP surgery, so set the alarm for 10:33 am and keep that appointment detail close at hand. There are 27 minutes until 11:00 am, enough time to check the surgery address, find your keys and prepare to leave without repeatedly checking the time.

While you wait for the prescription collection, this alarm can continue running when its page sits behind another page in the same browser. Some browsers may reduce activity on a page left in the background, so keep the alarm page open and return to it shortly before 10:33 am to confirm that it is still active and the volume is audible. If the browser is closed or the phone goes to sleep, however, the prescription reminder cannot sound.

Before setting off for the GP surgery late in the morning, check how the outdoor air feels as well as the temperature. High humidity can make a mild UK morning feel rather stuffy, while drier air may feel cooler in a breeze. A light layer that is easy to remove is practical for the walk, and leaving a little time for fresh air avoids turning the prescription collection into a rushed departure.

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 10:33 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.