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Comment by 0x0203 | Hacker News Reader

Another consideration might be to switch 24 to 0 or 00. I've seen a lot of 24 hour clocks that use 24 and I'm not sure why this ever happened since there is no time in hour 24. 12:15 AM/PM is a real thing for a 12-hour clock, but 24:15 isn't, as far as I'm aware. Unless some people consider that to be the very first hour of the day, but that seems like it would invite more confusion.

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Tangently related, but working timetables on the London Underground run to 2330, 2345, 2359, but then rather than going to 0000, because the post midnight services (until about 0400) are on the previous date, they then go

2359

2400

2401

And on to 2459, 2500, 2501 etc.

(At least they used to before 24 hour running, not sure about now)

23:59, 1:00:00, 1:00:01 would have been better.

The latter two could be confused with hour:minute:second

I saw this often in open/close times on bars in Japan in my trip there a couple weeks ago. I saw as high as 28:00

24:00 is a real time. See: https://en.wikipedia.org/wiki/24-hour_clock#Midnight_00:00_a...

> there is no time in hour 24

Doesn't matter. 24 marks the end of the day.

One advantage of using 24 instead of 0 is it makes it immediately obvious that this is a 24 hour clock. Otherwise you have to read the 0, see the 23 next to it, and infer that it's 24 hours, which takes a moment if you are not expecting it.

I used to work with a delivery route planning system that had 24:00 as midnight on one day, and 00:00 was midnight on the following day — the same “instant” but on two different days.

I forget the reasoning, but I remember it being described to me as both necessary and a reasonably common construct.

I've just added a setting for midnight to be 0 instead of 24, have a look

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