Subject: I Did Not Know This
File under “Learn something new every day”

For example, take “a.m.” and “p.m.”  People in the U.S. 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”). 

https://apple.news/Aibs2L9VrRA...