Set the alarm clock for 11:58 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 11:56 am Alarm clock for 11:57 am Alarm clock for 11:59 am

Going to bed for a 11:58 am alarm

Asleep by 2:43 am — 6 full sleep cycles, about 9 hours
Asleep by 4:13 am — 5 full sleep cycles, about 7 hours
Asleep by 5:43 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.

11:58 am across the country

London	11:58 am
Birmingham	11:58 am
Manchester	11:58 am
Glasgow	11:58 am
Belfast	11:58 am

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

How to use the online alarm clock

Getting ready early for your Oxfam charity-shop shift leaves room to check your keys, name badge and travel plans before you must leave. An alarm set for 11:58 am can mark the moment to finish packing and head out, with 12:00 pm arriving just afterwards rather than catching you halfway through another task.

While you prepare for the shift, the alarm page may sit behind a journey planner or a message to a colleague. Moving its tab into the background does not remove the alarm, but the browser may restrict background activity to conserve power, so keep the page open and make sure sound is allowed. If you close the browser completely or let the phone sleep, the alarm cannot sound, so your Oxfam shift needs a separate backup if missing the departure time would cause trouble.

Leaving for a late-morning charity-shop shift can mean stepping from a warm street into strong air conditioning close to noon. Keep a light layer within reach rather than buried beneath donated items or lunch, especially if you will work near the entrance where temperatures change whenever the door opens. A drink packed beside your keys also avoids a last-minute search at 11:58 am.

Common questions

What happens if my laptop goes to sleep before 11:58 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.