Set the alarm clock for 5:23 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 5:21 am Alarm clock for 5:22 am Alarm clock for 5:24 am Alarm clock for 5:25 am

Going to bed for a 5:23 am alarm

Asleep by 8:08 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:38 pm — 5 full sleep cycles, about 7 hours
Asleep by 11:08 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.

5:23 am across the country

London	5:23 am
Birmingham	5:23 am
Manchester	5:23 am
Glasgow	5:23 am
Belfast	5:23 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 halfway through another job when 5:23 am arrives and it is time to break away to put the Royal Mail sack out. An alarm at that exact minute gives you a clear stopping point, rather than letting the task carry you towards 6:00 am and risking a missed collection. The sound marks the moment to leave what you are doing and handle the sack.

While you finish the job already in progress, the alarm page may sit behind another tab without remaining visible. It should continue counting, although browsers can restrict background activity, so keeping this page open and the phone or computer awake makes the alert more dependable. If the alarm page is closed or the phone or computer sleeps, no sound will remind you about the Royal Mail sack. Checking the volume beforehand also avoids discovering too late that the alert was muted.

Moving through the house before dawn can disturb anyone still asleep, especially when doors, keys and the sack are handled in a rush. Leaving shoes, keys and a coat together near the exit reduces searching at 5:23 am. A moderate alarm volume placed close by can be heard without carrying as strongly into nearby bedrooms, while preparing the route to the door keeps the interruption brief.

Common questions

What happens if my laptop goes to sleep before 5:23 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.

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.