Amazing. I had no idea there was such a difference between versions. I suppose that the 24-hour clock is more widely used in Europe though.
It is the way we tell time officially. However, we (in Germany) don't say its 14hundred o'clock, we write it as 14:00 and say its 14 o'clock. When it's rather obvious that it is 2 o'clock in the afternoon as opposed to 2 o'clock in the morning, we do use the simple form and say its 2 o'clock instead of 14, just as the U.S. population does not use the a.m. and p.m. while conversing when its painfully obvious.
G.