AM means before noon. This is the 12-hour period from midnight to noon. PM means after noon. It covers the 12 hours from noon to midnight. Using numbers from 1 to 12, followed by am or …

This eventually evolved into the two 12-hour periods which are used today, one called "a.m." starting at midnight and another called "p.m." starting at noon. [1] The 12-hour clock can be …

AM definition: 1. I form of be: 2. used when referring to a time between twelve o'clock at night and twelve…. Learn more.

AM and PM are the abbreviated terms for Ante Meridiem and Post Meridiem respectively. While AM represents the time from midnight to 11:59 noon, and PM represents the time from 12 …

In particular, AM stands for ante meridiem, which translates into English as ‘before midday’. Meanwhile, PM is post meridiem and means in English ‘after midday’. These abbreviations are …

The first is referred to as am, which stands for ante meridiem, “before midday” in Latin, while the second is referred to using pm, meaning post meridiem, or “after midday.” This nomenclature …

Oct 3, 2019 · Do you capitalize a.m. and p.m.? In formal writing, it is best to lowercase both a.m. and p.m. and retain the periods (as opposed to writing them AM / PM or am/pm); however, …

Jul 2, 2025 · Turns out, the answer goes back to ancient Rome and the way they watched the sky. Quick insight: a.m. means “ante meridiem” or “before midday.” p.m. means “post meridiem” or …

When emphasizing an exact or precise time, the abbreviations “a.m.” and “p.m.” are used. These two abbreviations stand for the Latin terms “ante meridiem” and “post meridiem,” which literally …

Usage Note: By convention, 12 am denotes midnight and 12 pm denotes noon. Because of the potential for confusion, it is advisable to use 12 noon and 12 midnight.