Set the alarm clock for 8:39 am

 

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

The alarm goes off in: ::
 
 

Going to bed for a 8:39 am alarm

  • Asleep by 11:24 pm — 6 full sleep cycles, about 9 hours
  • Asleep by 12:54 am — 5 full sleep cycles, about 7 hours
  • Asleep by 2:24 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.

8:39 am across the country

Sydney8:39 am
Brisbane8:39 am
Adelaide8:09 am
Perth6:39 am
Darwin8:09 am

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

How to use the online alarm clock

Between the commute and the first coffee, 8:39 am is often the last checkpoint before the day properly starts. This tool sets a browser alarm for 8:39 am that rings through your device's speakers, handy for a desk you're already sitting at or a laptop open on the kitchen bench.

Set your preferred sound, press Start, then leave the tab where it is. Everything happens inside the browser — no background app, no notification pushed from a server — so an open tab is what actually makes the alarm ring at the right time.

Some people use this alongside a phone alarm rather than instead of it: a louder backup through laptop speakers, or a way to set a reminder without touching a phone at all. It won't survive the tab closing or the device sleeping, so for anything critical overnight, keep a second alarm running as well. On a 24-hour clock 8:39 am is written 08:39, and spoken aloud it's twenty-one minutes to nine in the morning. You'll also see it written 8.39 am — a full stop instead of the colon means the same time. If you need it loud, turn the system volume up before you start: the alarm plays at whatever the device is set to.

Common questions

Can I set more than one alarm at a time?

This page is built around a single alarm at a time. For multiple alarms, open a separate tab for each one and set a different time in each, keeping every tab open until it's rung.

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.