I notice that Prudie has added 'hours' to a time above. If I recall correctly, the British army has always done that (e.g. "The exercise will commence at 0200 hours") whereas the Royal Navy has never done so. (e.g. the exercise will commence at 0200"). I think, but I'm not sure, that RAF has followed the naval pattern.
When speaking 24-hour times, rather than when writing them down, there are also disagreements about whether a leading '0' should be referred to as 'oh' or 'zero' and whether 'on the hour' times should be referred to as 'hundred' or 'double zero'. Some times just don't sound right anyway. For example, when using the station PA system, I never referred to either the 'oh-oh-forty-two' departure or the 'zero-zero-forty-two' departure. 'Midnight forty-two' sounded much better to me!