[hetman]

The biggest difficulty for people will be forming new habits. The military time convention is familiar but cumbersome. Saying "I'll see you at 17 hundred hours" is not as convenient as "I'll see you at 17 o'clock" or simply "I'll see you at 17". The latter two sound a bit weird (especially the last one), but they're perfectly natural in other languages so it's just a matter of figuring out how to overcome the initial unfamiliarity in a large part of the population. I for one think this would be a great thing to standardise on just like SI.