AM PM Meaning: Complete Guide to 12-Hour Time
AM-PM.nl is your guide to time: from AM/PM explained to atomic clocks, world times and Dutch holiday calendars. Always accurate — always informative.
Central European Time (CET/CEST) · Synchronised via your browser
What Does AM and PM Mean?
AM and PM are abbreviations from Latin that indicate whether a time falls before or after noon. They are used in the 12-hour clock system, popular in the United States, United Kingdom and other English-speaking countries.
”Before midday” — from midnight to 11:59 in the morning.
12:00 AM = Midnight (00:00)
”After midday” — from noon to 11:59 in the evening.
12:00 PM = Noon (12:00)
In the Netherlands and most of Europe, the 24-hour notation is standard. This is unambiguous: 14:30 is always in the afternoon, 02:30 always at night — no need for AM or PM.
AM/PM Conversion Table
| 12-hour (AM/PM) | 24-hour | Description |
|---|---|---|
| 12:00 AM | 00:00 | Midnight |
| 1:00 AM | 01:00 | Night |
| 6:00 AM | 06:00 | Early morning |
| 9:00 AM | 09:00 | Morning |
| 11:00 AM | 11:00 | Late morning |
| 12:00 PM | 12:00 | Noon |
| 1:00 PM | 13:00 | Afternoon |
| 6:00 PM | 18:00 | Early evening |
| 9:00 PM | 21:00 | Evening |
| 11:59 PM | 23:59 | Just before midnight |
Mnemonics: How to Remember AM and PM
- Ante = Always before noon
- A comes before P in the alphabet → AM comes first in the day
- After Midnight (from midnight to noon)
- Post = Past midday
- Passes Midday
- Pre Midnight (from noon to midnight)
Military Time
In the military, aviation, medicine and emergency services, the 24-hour clock is always used. In American English, this is called “Military Time”. Time is expressed as a 4-digit number:
| 12-hour | 24-hour | Military | Spoken as |
|---|---|---|---|
| 12:00 AM | 00:00 | 0000 | ”Zero-zero-zero-zero hours” |
| 6:00 AM | 06:00 | 0600 | ”Zero-six-hundred hours” |
| 12:00 PM | 12:00 | 1200 | ”Twelve-hundred hours” |
| 3:00 PM | 15:00 | 1500 | ”Fifteen-hundred hours” |
| 10:00 PM | 22:00 | 2200 | ”Twenty-two-hundred hours” |
Explore AM-PM.nl
Frequently Asked Questions about AM and PM
What does AM and PM stand for?+
AM stands for 'Ante Meridiem', Latin for 'before midday'. PM stands for 'Post Meridiem', meaning 'after midday'. The 12-hour clock uses AM for 00:00–11:59 and PM for 12:00–23:59. Most European countries use the 24-hour clock instead.
What is 12:00 AM and 12:00 PM?+
12:00 AM is midnight (00:00 in 24-hour notation). 12:00 PM is noon (12:00 in 24-hour notation). This is the most confusing part of the AM/PM system: exactly at the transition point, the designation switches.
How do I convert AM/PM to 24-hour time?+
For AM times: keep the hour as-is — but 12 AM = 00:00. For PM times: add 12 to the hour — but 12 PM stays 12:00. Examples: 3:30 PM = 15:30 | 11:00 AM = 11:00 | 12:00 AM = 00:00 | 12:00 PM = 12:00.
Is 12-hour or 24-hour time more common globally?+
The 24-hour clock is used by the majority of the world, including all of Europe, most of Asia, Africa, and Latin America. The 12-hour AM/PM clock is primarily used in the United States, Canada (mixed usage), the United Kingdom and a few other English-speaking countries.
What is military time?+
Military time is essentially the 24-hour clock, but expressed as a 4-digit number without a colon. For example: 14:30 = 1430 hours (pronounced 'fourteen thirty'). It is used by the military, aviation, medicine and emergency services worldwide to avoid any ambiguity between AM and PM.