Set the alarm clock for 10:21 pm

 

Leave this tab open — the alarm only rings while the tab stays open.

The alarm goes off in: ::
 
 

10:21 pm across the country

Sydney10:21 pm
Brisbane10:21 pm
Adelaide9:51 pm
Perth8:21 pm
Darwin9:51 pm

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

How to use the online alarm clock

An alarm at 10:21 pm close to midnight is a common way to draw a line under a long day: log off, finish the load of washing, get to bed. Set the time here and it'll ring at 10:21 pm through your laptop or desktop speakers.

Choose a sound before you press Start — something like a chime or a classic bell tends to work better than anything too gentle. Once it's running, the countdown happens right here in the browser, which means the tab needs to stay open in the background rather than being closed.

Unlike a phone alarm, this one won't ring if you close the tab, put the computer to sleep, or shut the lid, so it suits a desk, a kitchen bench, or anywhere the device stays powered on and awake. It's free to use and doesn't need an account, but it's not built for unattended overnight use. On a 24-hour clock 10:21 pm is written 22:21, and spoken aloud it's twenty-one minutes past ten at night. Written the Australian way that's 10.21 pm, and typed in a hurry it's often 10:21pm. Setting the alarm to 10:21 pm tomorrow morning works the same way: if the time has gone for today, the count runs through to it.

Common questions

Why use a browser alarm instead of my phone's built-in one?

Mainly for reliability against silent mode, do-not-disturb, or a phone left charging out of earshot. It's a useful backup or a desk-based alternative, though it depends on this tab staying open rather than running in the background of your phone.

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.