How to use the online alarm clock
An alarm for 12:47 am is usually about catching something before the rest of the world is awake: a ferry, a flight, or a change of shift. Set the time, pick a tone, and leave this tab open. At 12:47 am it'll ring through your device's speakers until you tell it to stop.
Select a sound, hit Start, and that's the whole setup. The countdown runs inside this browser tab rather than on your device's operating system, so it needs to remain open, on a phone or laptop, until the alarm actually goes off.
It's free to use, doesn't need an account, and works the same in any modern browser, but it's honestly not meant to replace your phone for anything you can't afford to sleep through. Keep the tab open and the device awake, and it'll ring reliably at the time you set. On a 24-hour clock 12:47 am is written 00:47, and spoken aloud it's thirteen minutes to one at night. Timetables and rosters may show it as 00:47, and handwritten notes as 12.47 am. Setting the alarm to 12:47 am tomorrow morning works the same way: if the time has gone for today, the count runs through to it.
Common questions
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.
Can I change the alarm sound?
Yes, there's a short list of tones to choose from before you press Start. Pick whichever one you're most likely to actually hear — softer sounds are easier to sleep through than a firm chime or bell.
What happens once the alarm goes off?
It rings through your device's speakers on a loop until you stop it from this page. There's no separate app notification, so make sure your volume is turned up before you rely on it.
Is this alarm accurate across daylight saving time?
It uses your device's local clock, so as long as your computer's time and date settings are correct, it'll adjust automatically when daylight saving time starts or ends.