Set the alarm clock for 4:23 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 4:21 am Alarm clock for 4:22 am Alarm clock for 4:24 am Alarm clock for 4:25 am

Going to bed for a 4:23 am alarm

Asleep by 7:08 pm — 6 full sleep cycles, about 9 hours
Asleep by 8:38 pm — 5 full sleep cycles, about 7 hours
Asleep by 10:08 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.

4:23 am across the country

Sydney	4:23 am
Brisbane	4:23 am
Adelaide	3:53 am
Perth	2:23 am
Darwin	3:53 am

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

Online alarm clock for 4:23 am

You have just woken at 4:23 am for a domestic flight north, with the packing, dressing and trip to the airport still ahead. Let the alarm mark the moment to sit up and begin, rather than drifting back under the doona. There are 37 minutes until 5:00 am, enough for a calm check of your bag, identification and terminal details before you leave.

Because your departure depends on waking before the household is moving, keep the alarm running where you set it and prevent the screen from going to sleep. A domestic flight could be missed if the browser stops running or the phone sleeps before the alarm time, because no sound will play. Set the volume clearly above the quiet room, connect power if the battery is low, and use a separate phone alarm as a backup for the airport run.

Before an early northern flight, choose something quick and familiar if you want food now: toast, a banana or a small bowl of cereal will not hold up getting ready. Have some water while checking your bag, especially if the next easy chance for a drink is after reaching the terminal. Leave a large breakfast, repeated coffees or anything messy to prepare until later; at this hour, fewer kitchen jobs make it easier to get out quietly and on schedule.

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.