12 AM vs 12 PM: Which Is Midnight and Which Is Noon?

12 AM is midnight and 12 PM is noon. In military time, 12 AM is 0000 and 12 PM is 1200, which removes the confusion completely.

Why 12 AM and 12 PM Confuse People

AM stands for ante meridiem (before noon) and PM for post meridiem (after noon). Noon itself is neither before nor after noon, and midnight is 12 hours before noon and 12 hours after it. The National Institute of Standards and Technology (NIST) calls 12 a.m. and 12 p.m. ambiguous for that reason.

The common convention follows digital clocks: the display switches to PM at 12:00 noon, so 12:00 PM is noon and 12:00 AM is midnight.

12 AM and 12 PM in Military Time

Standard time	Military time	Meaning
12:00 AM	0000	Midnight, start of the day
12:30 AM	0030	Half an hour after midnight
12:00 PM	1200	Noon
12:30 PM	1230	Half an hour after noon
11:59 PM	2359	Last minute of the day

A Simple Way to Remember

• 12 AM starts the day. The day’s AM hours run from 12 AM to 11:59 AM.
• 12 PM starts the afternoon. The PM hours run from 12 PM to 11:59 PM.

The Hour After Midnight

Times from 12:00 AM to 12:59 AM use hour 00 in military time: 12:05 AM is 0005 and 12:45 AM is 0045. Writing 12:45 AM as 1245 turns it into a lunchtime time.

Safe Ways to Write Deadlines

A deadline of “midnight Friday” can mean the start of Friday or the end of it, a full day apart. 4 safer forms remove the doubt:

1. 11:59 PM Friday for the end of Friday.
2. 12:01 AM Friday for the start of Friday.
3. Friday 2359 in military time.
4. Friday 2400 to mark the end of Friday, or Saturday 0000 for the same moment.

NIST suggests 11:59 p.m. or 12:01 a.m. for contracts and deadlines.

Quick Answers

• Is 12 AM morning or night? Midnight, the very start of the morning.
• Is 12 PM lunchtime? Yes, 12 PM is noon.
• Is 1200 midnight? No, 1200 is noon; midnight is 0000.

Read the full guide to midnight in military time, or open the 0000 and 1200 pages.