[Taywee]

I find it frustrating that the explanation of the schedule switches from a 24-hour clock to apparently a 12-hour clock without AM or PM designation

> From as early as 21:00 to 23:00, those fortunate enough to afford them would begin flopping onto mattresses...A couple of hours later, people would begin rousing from this initial slumber. The night-time wakefulness usually lasted from around 11:00 to about 01:00

[aparticulate]

My theory— In the UK, 24-hour is used much more in writing than in other parts of the anglosphere, but no Brit uses 24-hour in speech. I reckon the typo occurs when people have to convert from their "speaking" brain to their "writing" brain.

[zarzavat]

That and because British people are used to thinking in both systems and implicitly converting between them, they may not even notice the inconsistency. Whereas for Americans who are used to the 12 hour system, the discrepancy sticks out much more strongly.

[quickthrower2]

As a Brit and a developer who has ploughed through many a 24h format log entry, I agree!