If you have ever looked at a hospital medication roster, an airline flight plan, or an emergency dispatch log and hesitated between writing 0000 and 1200, you are not alone. Converting the 12th hour between standard 12-hour AM/PM and 24-hour military (army) time is the single most searched timekeeping question on the internet.
The confusion stems from civilian clocks: we count up to 12:00 in the morning, immediately switch to "PM" at noon, and then repeat 12 hours later at midnight. In military time, clocks never repeat.
• 12:00 PM (Noon) =
1200 (Twelve Hundred Hours)
• 12:00 AM (Midnight) =
0000 (Zero Hundred Hours)
Need an instant conversion or shift calculation? Launch our free Military Time Converter & Shift Duration Calculator.
1. What is 12:00 PM (Noon) in Military Time?
12:00 PM (civilian noon) translates to exactly 1200 in military time.
A 24-hour calendar day begins at midnight. By the time the clock strikes noon, exactly 12 complete hours have passed in that day. Therefore, the hour indicator is 12, followed by the two-digit minute counter 00.
- Pronounced: "Twelve Hundred Hours" or simply "Twelve Hundred".
- NATO Radio Comms: "One Two Zero Zero Hours".
2. What is 12:00 AM (Midnight) in Military Time?
12:00 AM (civilian midnight) is written as 0000 in military time.
Because midnight marks the exact moment a brand-new 24-hour day begins, zero hours and zero minutes have elapsed in that new date.
- Pronounced: "Zero Hundred Hours" or "Zero Zero Zero Zero".
- One minute past midnight (12:01 AM): Written as
0001.
3. The 2400 Mystery: When Do You Use 0000 vs. 2400?
A common question among emergency responders and medical staff is: "Does 2400 actually exist?"
The answer is yes, but strictly to designate the end of an operational day. Both 0000 and 2400 point to the exact same second on a master atomic clock. However, in professional documentation:
0000marks the start of a day: A duty shift scheduled for "Monday 0000 to Monday 0800" begins first thing Monday morning.2400marks the conclusion of a day: A hospital contract ending on "Friday 2400" means your shift concludes at the very last second of Friday night before Saturday begins.
Comparison: The 12th Hour Transition Table
| Civilian (12-Hour) | Military (24-Hour) | Pronunciation | Context |
|---|---|---|---|
| 11:00 AM | 1100 |
"Eleven Hundred" | Late morning |
| 11:59 AM | 1159 |
"Eleven Fifty-Nine" | One minute before noon |
| 12:00 PM (Noon) | 1200 |
"Twelve Hundred" | Midday / Lunch |
| 12:01 PM | 1201 |
"Twelve Zero One" | Early afternoon |
| 1:00 PM | 1300 |
"Thirteen Hundred" | Afternoon (1 + 12 = 13) |
| 11:59 PM | 2359 |
"Twenty-Three Fifty-Nine" | Final minute of the day |
| 12:00 AM (Midnight) | 0000 / 2400 |
"Zero Hundred" / "Twenty-Four Hundred" | Day start (0000) or cutoff (2400) |
| 12:01 AM | 0001 |
"Zero Zero Zero One" | First minute of new day |
4. Why Armed Forces & Hospitals Avoid AM and PM
In everyday civilian life, mistaking 8:00 AM for 8:00 PM is an inconvenience. In military operations, aviation flight planning, and intensive care units, that exact mistake can have catastrophic consequences.
If a doctor writes "administer 100mg IV at 8:00", nursing staff might administer medication 12 hours late. By recording 0800 versus 2000, handwritten or verbal confusion is mathematically impossible.
Frequently Asked Questions
What is 12 PM in military time?
12:00 PM (Noon) in military time is 1200 hours. It is pronounced "Twelve Hundred Hours".
What is 12 AM in military time?
12:00 AM (Midnight) in military time is 0000 hours. It is pronounced "Zero Hundred Hours".
When is 2400 used instead of 0000?
0000 designates the beginning of a calendar day, while 2400 is used on shift schedules and duty logs to indicate the absolute conclusion or cutoff of an operational day.