>>>Even better, come November, we'll have an interesting second (twice):
>>
>>Once. Unless you share the common illusion that the day has 12 hours twice. We learn that it has 24 hours.
>
>If a day has twenty four hours how many does a night have ?

A day has 24 hours plus the night - just as the week has seven days and the weekend.

>We're also under the illusion that the year has 30 odd days twelve times over. We learn that it has 365.....

We're on the wrong planet. We'd need one with 256 days with 32 hours each. Or something equally smooth so our love for round numbers and ease of programming would be satisfied.

>Anyway the use of the 24hr notation is pretty recent outside scientific use. Even the military were using a twelve hour clock during WW1. I think only the advent of digital watches made the 24hr notation more acceptable to most people - and I still very rarely hear it used in general conversation. When was the last time you agreed to meet someone at the pub at 2030 hrs ?

There aren't two thousand hours in a day, no matter what they say :). At 20:30, well, we do use that when there can be any confusion... like "wake me up at 16", or when one wakes up in a winter night, sees it's 7, but doesn't know whether it's morning or evening.

OTOH, you won't see a poster advertising an event starting at 4 - it'll be at 16:00, or 19:30 or whatever. TV schedules in all the newspapers or websites also have 24-hour notation. One possible hurdle with 2x12 is that we don't use am/pm (Latin is not that popular), and any pair of expressions we regularly use can't be abbreviated. One pair is ujutro/uveče (in the morning/in the evening), which would be u/u, or uj/uv (looks silly), or prepodne/poslepodne (beforenoon, afternoon), a pp/pp :).