1pm is afternoon - so is 12pm
8am is morning - so is 12am
never mind the plughole or the equator. This applies in leap years and is unrelated to the venereal equinox
Surely 12 noon should be 12m as in 12 meridian as am is anno meridian (before the meridian) and pm is post meridian (after the meridian) so the instantaneous moment that is noon is the meridian. Haven't a clue about midnight
To be totally anal about this, 1200 hours rarely exactly corresponds to the meridian. At Greenwich for example, 1200 GMT occurs before the meridian from January to mid-March and again July to mid August, and after at other times of the year.
So perhaps we should be talking about noon being 12am now, but in a week or so it will be 12pm. And at the end of March we're onto BST, so back to 12am again. ;-)
1200 is 1200 and the date is the day's given date. But 2400? Is that tomorrow, yesterday or today? Thus the military, when they give a date time reference NEVER use 2400, but 2359 or 0001 and a given date.
Perhaps if you were given an order to carry out on 2400 on say the 15th of March you would realize that the ambiguity would either make you a day early of a day late and that this would get you some extra time peeling potatoes no matter what you decided to obey. However if you were able to get a bucket of steam or a lefthanded fork as well, then I withdraw my objection.
Lets not get too scientific here,......12 Noon, be it AM or PM is, in my opinion....................a perfect time for a pint! "Oh look its Beer-o-clock, time for a pint!"