Japanese VCRs could be programmed with times like 24/25/26/27:xx, which makes a lot of sense for TV programs that are part of “today’s” schedule but after midnight. Much lower risk of getting the day wrong when programming.

Back when I was a night owl, I considered “today” to last until about 5am when you start hearing birds outside. Aligning semantic days with your schedule is incredibly convenient.

Now that I’m a morning person, the same concept of 5am semantic days still works perfectly. The day begins about 20min before my alarm.

Actually it is pretty elegant system. Bit strange and extra calculation, but rather elegant option to pick.

You occasionally see times like 24:15 on European railway timetables. If the train runs only on weekdays, it might make it clearer that there isn't one at 00:15 on Monday.

I haven't noticed 25:00, but I don't often look at printed/PDF timetables nowadays.

I've seen this when working on a side project involving public transport timetables from Google Transit. A service can run on 26:00 on Sunday, to indicate that the Sunday service is running 2 hours past midnight (i.e. on Monday 02:00).

https://developers.google.com/transit/gtfs/reference#stop_ti...

Surprisingly, I like that as an informal system

I don't get it.

I think:

If a coffee shop opens at 5am, they say that. They never say 29.

If a bar stays open UNTIL 5am, they say 29.

Yep, and this makes it clear that they are NOT open Sunday because Saturday closes at 29 and there are no hours listed for Sunday.

Your flight leaves at 23 and arrives at 26. (11 PM to 2 AM next day)

Your return flight leaves at 2 and arrives at 11. (2 AM to 11 AM that same day)