In Europe we use the 24-hour system to write time, but a 12-hour system to speak about it. So you're invited to dinner on Saturday at 6 (nobody in their right mind would show up at 0600). Everybody learns at an early age that 4 o'clock in the afternoon is 16, 5 is 17, etc. It's easy when there are analog clocks in all public, walkable spaces, as well as in the kitchen and/or living room.

In French, we say "viens à 21 heures," or "come at 21 hours," quite literally. Yes, "hours" is a duration as one poster commented; and yes, also in French. But the context gives the meaning away.

Well, in English, you can't say "16 o'clock", can you? You can only say "sixteen hundred hours" (which sounds terrible, if you ask me).

> Well, in English, you can't say "16 o'clock", can you? You can only say "sixteen hundred hours"

What's stopping you?

Nothing, get enough people saying it and it will become the thing.

I'd vote for sixteen hour or something similar.

That's how they say it in Germany...sechzehn uhr

Yep, thats why I'm voting for it in English too. Just use the German method and keep it simple.

In French : 16 hours (seize heures) In Polish even simpler: 16-th (szesnasta)

16 o'clock sounds just fine.

Yeah, sixteen hundred hours sounds awful. Sixteen o-five sounds OK to me though.

You can if you're George Orwell writing 1984:

“It was a bright cold day in April, and the clocks were striking thirteen."

how about "16 hours" or "1600"

“hours” denotes a duration. Times and durations should be distinguishable to avoid ambiguity. 16 o'clock = time, 16 hours = duration.

16 hours is shortcut for 16 hours from midnight.