Using the month as a prefix seems more logical to me. It makes you immediately aware of the time of the year.
Americans in general have no conception of the 24 hr clock, they will say for example 21:32pm...the pm is unnecessarywhy do the yanks do that? i cant see any benefit its slightly more awkward really.
Quite possibly, but why for England? do they add subtitles for none english speaking countries?are you basing that on mythbusters where the narator is doing it for the european market?
they presenters still use miles per hour or feet per second...