Set the alarm clock for 3:29 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 3:27 am Alarm clock for 3:28 am Alarm clock for 3:30 am Alarm clock for 3:31 am

Going to bed for a 3:29 am alarm

Asleep by 6:14 pm — 6 full sleep cycles, about 9 hours
Asleep by 7:44 pm — 5 full sleep cycles, about 7 hours
Asleep by 9:14 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.

3:29 am across the country

London	3:29 am
Birmingham	3:29 am
Manchester	3:29 am
Glasgow	3:29 am
Belfast	3:29 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 wait to leave the university library’s night reading room at 3:29 am, keep the alarm visible rather than repeatedly checking the clock. The set moment falls well before 4:00 am, so there is still enough time to finish the paragraph in front of you, gather your notes and return any reference books without rushing.

Your reading-room departure depends on the browser remaining ready to play the alert. Set the alarm for 3:29 am, check that the sound is audible, and leave this page open while you continue studying. If you close the page or browser, or allow the computer to sleep, the university library departure alarm will not sound. A phone alarm is a sensible backup if you might shut the laptop before packing your bag.

Leaving a quiet library in the middle of the night is easier when food does not add another task at the last minute. If you are slightly hungry, finish a small snack that will not scatter crumbs across your notes, and have some water before you pack it away. Save a full meal or another hot drink until after 3:29 am, especially if buying it would delay your exit or leave you carrying an open cup through dark corridors and towards the night bus.

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 3:29 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.