Table of contents:
Are you interested in calculating military (24-hours) time? Use our calculator below to make your conversion.
Each day has 24 hours. Converting from 24-hour time to 12-hour time can cause confusion.
Use 00:00 to signify midnight in a 24-hour time.
Eliminate “AM” for the hours between 1:00 and 11:59 AM.
Leave the noon hour as-is, but remove "PM."
Add 12 to the hours between 1:00 and 11:59 PM and eliminate "PM.
Converting AM/PM to 24-hour clock
Converting 24 hour clock to AM/PM
Here is a side-by-side comparison of the 24-Hour Clock (military time) and AM/PM:
12-hour am-pm clock | 24-hour military clock |
|---|---|
12:00 midnight (start of the day) | 00:00 |
01 : 00 am | 01 : 00 |
02 : 00 am | 02 : 00 |
03 : 00 am | 03 : 00 |
04 : 00 am | 04 : 00 |
05 : 00 am | 05 : 00 |
06 : 00 am | 06 : 00 |
07 : 00 am | 07 : 00 |
08 : 00 am | 08 : 00 |
09 : 00 am | 09 : 00 |
10 : 00 am | 10 : 00 |
11 : 00 am | 11 : 00 |
12 : 00 pm | 12 : 00 |
01 : 00 pm | 13 : 00 |
02 : 00 pm | 14 : 00 |
03 : 00 pm | 15 : 00 |
04 : 00 pm | 16 : 00 |
05 : 00 pm | 17 : 00 |
06 : 00 pm | 18 : 00 |
07 : 00 pm | 19 : 00 |
08 : 00 pm | 20 : 00 |
09 : 00 pm | 21 : 00 |
10 : 00 pm | 22 : 00 |
11 : 00 pm | 23 : 00 |
12:00 midnight (end of the day) | 24:00 |
Note: "12 AM" and "12 PM" can cause confusion, so we prefer "12 Midnight" and "12 Noon".
24-hour clock – where is it used?
The 24-hour time clock system is the most used in the world and is the international standard notation of time. (ISO 8601).
The United States, Great Britain, Ireland, Canada, Australia or New Zealand the 12-hour AM/PM format is still more commonly used. In these countries, the 24-hour format is called 'Military time'.
Should "AM" be "ante meridiem" or "ante meridian" (likewise for PM)?
The official (according to an American, Australian and British dictionary I checked), and most common spelling for AM is "ante meridiem" which is a Latin phrase. I recommend that spelling!
But people sometimes use the phrase "ante meridian" (a "meridian" in this case refers to an imaginary line in the sky when the sun is at its highest point).
The 24-hour time format is usually used in transportation, medical and military industries to avoid confusion.