Set the alarm clock for 5:12 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 5:10 am Alarm clock for 5:11 am Alarm clock for 5:13 am Alarm clock for 5:14 am

Going to bed for a 5:12 am alarm

Asleep by 7:57 pm — 6 full sleep cycles, about 9 hours
Asleep by 9:27 pm — 5 full sleep cycles, about 7 hours
Asleep by 10:57 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.

5:12 am across the country

Sydney	5:12 am
Brisbane	5:12 am
Adelaide	4:42 am
Perth	3:12 am
Darwin	4:42 am

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

Online alarm clock for 5:12 am

You have only just woken at 5:12 am, and the pool session before work is still a plan rather than something underway. Set the alarm for this time when you need a firm start for getting dressed, collecting your towel and goggles, and leaving while the streets are quiet. With 6:00 am approaching, there is enough room for a steady departure without turning the whole morning into a rush.

Your swim depends on hearing the signal at the moment you expect it, so test the alarm now at a low volume before relying on it. Listen for the chosen sound, check that the volume is audible, then reset it to 5:12 am. A browser alarm may fall silent if its page is no longer active or the phone enters sleep, which could leave your pool training without its planned wake-up cue.

Leaving for an early swim can disturb people who are still asleep, even when the alarm itself lasts only a few seconds. Keep the phone close enough to silence it immediately, prepare your clothes and pool bag the night before, and avoid searching through cupboards at 5:12 am. If someone shares the room, vibration paired with a moderate sound can make the wake-up noticeable to you without carrying as sharply through the house.

Common questions

Is there a cost to use this?

No, it's free, with no sign-up and no limit on how many times you set it. It just needs the tab left open until the time you've chosen arrives.

Will the alarm still ring if I close the browser tab?

No. The alarm only runs while this tab stays open — closing it, or closing the browser entirely, stops the countdown before it can ring. Keep the tab open in the background if you need it to go off later.

Does the alarm work if my laptop goes to sleep?

Not reliably. If the device sleeps or the screen locks, the browser tab pauses along with it, so the alarm may not fire on time or at all. Adjust your power settings if you're relying on this over a longer stretch.

Do I need to create an account or download anything?

No, there's nothing to sign up for and nothing to install. Pick a time and a sound, press Start, and it runs entirely in this browser tab.