Set the alarm clock for 5:33 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 5:31 am Alarm clock for 5:32 am Alarm clock for 5:34 am Alarm clock for 5:35 am

Going to bed for a 5:33 am alarm

Asleep by 8:18 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:48 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:18 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.

5:33 am across the country

London	5:33 am
Birmingham	5:33 am
Manchester	5:33 am
Glasgow	5:33 am
Belfast	5:33 am

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

How to use the online alarm clock

While preparing to pass security before the ferry from Dover, set this 5:33 am alarm before packing the last documents or loading the car. It gives you a clear marker before the morning starts moving, with 6:00 am close enough to keep the departure routine focused without rushing every check.

Because the ferry journey depends on an early prompt, test the alarm sound now rather than discovering a problem when it should ring. Set it briefly for the next minute, confirm the volume is audible, then return it to 5:33 am. Keep the alarm running and the phone awake; otherwise the ferry reminder may remain silent, leaving no cue to start the drive or check-in preparations.

Before a Dover sailing, the surroundings may be unusually quiet when the alarm is set, yet road traffic, voices and vehicle movement can build as 6:00 am approaches. Choose a sound that is distinct from the low hum of a fan or car ventilation, and place the phone near enough to hear without burying it beneath clothing. If someone else is sleeping nearby, use a moderate tone backed by vibration on a firm surface, where the movement is noticeable without filling the room.

Common questions

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.

What happens if my laptop goes to sleep before 5:33 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.