AM and PM are Latin abbreviations that split the day into two 12‑hour parts in the 12‑hour clock system.

Quick Scoop: What does AM and PM mean?

  • AM stands for ante meridiem – Latin for “before midday.” It covers the time from 00:00 (midnight) to 11:59 in the morning.
  • PM stands for post meridiem – Latin for “after midday.” It covers the time from 12:00 (noon) to 23:59 (just before midnight).

Think of it like this:

Before lunch = AM, after lunch = PM.

How AM and PM relate to the 24‑hour clock

  • 00:00–11:59 (24‑hour) → AM.
  • 12:00–23:59 (24‑hour) → PM.

So:

  • 7:00 AM = 07:00
  • 7:00 PM = 19:00

A tiny style note (how to write them)

You might see them written as:

  • a.m. / p.m.
  • AM / PM
  • am / pm

All are used in modern writing; the key is to pick one style and stay consistent in the same text.

TL;DR:
“AM” means ante meridiem (“before midday”), and “PM” means post meridiem (“after midday”); AM is midnight to before noon, PM is noon to before midnight.

Information gathered from public forums or data available on the internet and portrayed here.