I Had Absolutely No Clue What “A.M.” And “P.M.” Actually Stand For, And I Bet You Don’t Either

For example, take “a.m.” and “p.m.”  People in the US are constantly thinking and talking about time in terms of a.m. and p.m., but if you ask someone what those letters stand for, you may be surprised how little people actually know about the abbreviations. 

Some say it’s “after midnight” or “past midday,” but that isn’t exactly true…

In fact, like many words and phrases in the English language, a.m. is short for a Latin phrase, “ante meridiem” (or “before midday”), while p.m. is short for “post meridiem” (or “after midday”).

While there isn’t a ton of information out there about when exactly a.m. and p.m. came into popular use in the English language, the 12-hour timekeeping system dates back to ancient Egypt and Mesopotamia. During the Renaissance period, mechanical clocks with 12-hour analog dials appeared in churches and palaces throughout Europe.