Set the alarm clock for 3:58 am

How to use the online alarm clock

Setting an alarm for 3:58 am while everyone else is asleep can feel like cheating the clock, but it's usually just planning ahead for an early departure or a shift that starts before sunrise. This will sound at 3:58 am through your speakers, whether it's the depths of winter or a short summer night.

Pick whichever sound you're most likely to actually notice, then press Start. The alarm is tied to this browser tab, so it needs to stay open. Minimising the window is fine, but closing the tab or the browser will stop the countdown before it ever rings.

The advantage of a browser alarm is volume and reliability at a desk: laptop speakers are often louder and easier to hear across a room than a phone left in a bag. The catch is that it depends entirely on the tab staying open; if the browser closes or the laptop sleeps, the alarm won't fire. On a 24-hour clock 3:58 am is written 03:58, and spoken aloud it's two minutes to four at night. Timetables and rosters may show it as 03:58, and handwritten notes as 3.58 am. Setting the alarm to 3:58 am tomorrow morning works the same way: if the time has gone for today, the count runs through to it.