Set the alarm clock for 9:33 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 9:31 am Alarm clock for 9:32 am Alarm clock for 9:34 am Alarm clock for 9:35 am

Going to bed for a 9:33 am alarm

Asleep by 12:18 am — 6 full sleep cycles, about 9 hours
Asleep by 1:48 am — 5 full sleep cycles, about 7 hours
Asleep by 3:18 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.

9:33 am across the country

London	9:33 am
Birmingham	9:33 am
Manchester	9:33 am
Glasgow	9:33 am
Belfast	9:33 am

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

How to use the online alarm clock

Finishing up before taking the dog to Hampstead Heath, you set the alarm for 9:33 am so leaving does not slip behind one last chore. It marks a clear moment to put on your coat, check the lead and head out, while still leaving enough of the morning to be walking before 10:00 am.

A Hampstead Heath departure needs a tone that suits the room you are leaving. A gentle sound may be enough when the phone is beside you in a quiet kitchen; a more persistent one makes sense if you are packing a bag or moving between rooms. The dog-walk reminder may not sound if the browser page is closed or the phone goes to sleep, so another alarm is sensible when missing 9:33 am would disrupt the outing.

Heading onto the Heath in the later morning can mean moving between bright open ground and shaded paths. Before leaving, checking the light outside helps with practical choices: sunglasses may be useful after a grey start, while a reflective detail on the lead can remain visible beneath trees. Keeping those items by the door makes the 9:33 am change from indoors to outdoors less fiddly.

Common questions

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.

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.