What does A.M. and P.M. actually mean?

Question

I have always wanted to know what they are short for... Is it a latin acronym?

Answer 1

According to both NASA and the British Royal Observatory, a.m. stands for ante-meridiem, which is from Latin for "before the Sun has crossed the line." And p.m. means post-meridiem, which is from Latin for "after the Sun has crossed the line." But what line are they talking about? If you look on most world maps, you'll see horizontal latitude lines and vertical longitude lines. These lines allow you to pinpoint any place on Earth. The longitude lines are also called meridians. So if you're standing at a meridian line and the Sun is directly overhead, it's noon at that spot. Before it arrives overhead, it's a.m. After the sun is overhead, it's p.m. Our Time category has lots more information about how time is calculated!

Answer 2

Just for the record... the proper way to word this question would be: "What do A.M. and P.M. actually mean?"

A.M. stands for the latim Ante Meridiem, literally, "before midday." P.M. stands for Post Meridiem, literally, "after midday."

The transition officially occurs when the sun crosses the Prime Meridian, the line of longitude (north to south) labeled 0 degrees. That line has actually changed location in the past.

Answer 3

ante meridan latin meaning before noon
post meridan latin meaning after noon

Answer 4

ante meridiem and post meridiem.

Ante means before (not against, like anti)
Post means after.
Meri = middle
Diem = day
It's Latin.

Answer 5

don't think it is short for acronym. its something about
after and pre something.

Answer 6

after midnight and ..hmm i dont know this one

Answer 7

hi, please refer to the url below:
http://wwp.greenwichmeantime.com/info/noon.htm