Additionally, the point of doing it the other way round is that the most important thing is on the left, where we start reading, followed by less important things. If I need to know the time of day, the hour is the most important thing, once I know whether it's 4 or 6, I can look at the minutes and first then do I perhaps (and does one really ever?) care about the seconds. As a matter of fact, my old wristwatch only had hour and minute hands... The opposite is true for the date. It starts, again, with the most significant thing on the left: the day. This assumes that people will probably have it easier to remember the month or year they live in.
And a final example: I have an appointment on the 24/01/2014 at 10:15:00. The most important questions are: What day do we have? And if it happens to be the 24th, what hour of the day is it? Is it 5? Good, 5h left. Is it 10? Oh boy, better look at the minutes...