24 Hour Clock Conversion: Military Time Made Simple
The 24 hour clock numbers the day straight through from 0000 to 2359 — no AM, no PM, no ambiguity. If you read timesheets, schedules, or payroll exports, you'll meet it constantly. The conversion takes one rule in each direction; here's the whole thing.
How the 24 hour clock works
Instead of running 1–12 twice, 24 hour time counts hours 0 through 23. Midnight is 0000, noon is 1200, and the day ends at 2359 before rolling over. Times are written as four digits — hours then minutes — so 0730 is 7:30 in the morning and 1945 is 7:45 in the evening. Spoken aloud in military style, 0730 is "oh-seven-thirty" and 1400 is "fourteen hundred."
The morning hours look identical to the 12-hour clock with a leading zero: 9:15 AM is 0915. The change happens after noon, when the count keeps climbing instead of resetting — 1:00 PM becomes 1300, 2:00 PM becomes 1400, and so on up to 11:00 PM at 2300.
You'll see the same system written with a colon (07:30, 19:45) in software and schedules. "Military time" and "24 hour time" mean the same thing; the only cosmetic difference is that military usage drops the colon and leading formats like "0000" vs "2400" for midnight — most systems use 0000 for the start of a day.
Converting 24 hour time to AM/PM
One rule: if the hour is 13 or greater, subtract 12 and call it PM. 1700 → 17 − 12 = 5:00 PM. 2130 → 21 − 12 = 9:30 PM. Minutes never change — only the hour converts.
Hours 1 through 11 are simply AM as written: 0600 is 6:00 AM, 1130 is 11:30 AM. That leaves two special cases people trip on: 0000 (or 24:00 on some displays) is 12:00 AM — midnight — and 1200 is 12:00 PM, noon. Hour 12 is the one hour that's PM without needing subtraction.
So the full decode order is: hour 0 → 12 AM; hours 1–11 → same hour, AM; hour 12 → 12 PM; hours 13–23 → subtract 12, PM. Run any timestamp through those four branches and you can't get it wrong.
Converting AM/PM to 24 hour time
The mirror-image rule: PM times from 1:00 to 11:59 add 12 to the hour. 3:45 PM → 1545. 8:00 PM → 2000. AM times from 1:00 to 11:59 stay as-is, padded to four digits: 8:05 AM → 0805.
The two specials flip the intuition: 12:00 AM (midnight) becomes 0000, and 12:00 PM (noon) stays 1200. A memorable way to hold it: in 24 hour time, the "12" hour only survives at noon; midnight resets to zero.
Quick self-test using a real shift: an employee works 8:30 AM to 5:15 PM. In 24 hour time that's 0830 to 1715 — and now the duration math is plain subtraction: 17.25 − 8.5 = 8.75 hours, before any unpaid break.
The full conversion reference
Midnight to morning: 0000 = 12:00 AM, 0100 = 1:00 AM, 0200 = 2:00 AM, 0300 = 3:00 AM, 0400 = 4:00 AM, 0500 = 5:00 AM, 0600 = 6:00 AM, 0700 = 7:00 AM.
Morning to afternoon: 0800 = 8:00 AM, 0900 = 9:00 AM, 1000 = 10:00 AM, 1100 = 11:00 AM, 1200 = 12:00 PM (noon), 1300 = 1:00 PM, 1400 = 2:00 PM, 1500 = 3:00 PM.
Afternoon to night: 1600 = 4:00 PM, 1700 = 5:00 PM, 1800 = 6:00 PM, 1900 = 7:00 PM, 2000 = 8:00 PM, 2100 = 9:00 PM, 2200 = 10:00 PM, 2300 = 11:00 PM.
Why payroll and time clocks use 24 hour time
AM/PM is where timesheet errors breed. A handwritten "in 7:00, out 3:30" could be a day shift or a night shift; a clock in 24 hours of 0700–1530 versus 1900–0330 can only mean one thing each. For businesses running evening or overnight shifts, that disambiguation alone justifies the format.
It also makes duration math mechanical. Hours subtract directly — 2200 to 0630 is clearly an overnight 8.5 hours once you handle the midnight rollover — and payroll systems compute on exactly this kind of continuous time value internally, even when they display AM/PM to be friendly.
You don't have to make employees think in military time to get the benefit: most time clock software accepts and displays either format while storing the unambiguous version underneath. But teaching your team to read 24 hour time takes about ten minutes with the reference above, and it permanently ends the "did you mean AM or PM?" follow-up.
Frequently asked questions
How do I convert 24 hour time to regular time?
If the hour is 13 or higher, subtract 12 and add PM — so 1700 is 5:00 PM. Hours 1-11 are AM as written, 1200 is noon, and 0000 is midnight (12:00 AM). Minutes never change.
What is 1430 in regular time?
2:30 PM. The hour 14 is greater than 12, so subtract 12 to get 2, keep the 30 minutes, and mark it PM.
Is military time the same as the 24 hour clock?
Yes — both count hours 0 through 23. Military style typically writes times without a colon (1545) and speaks them as "fifteen forty-five," while civilian 24 hour formats often use a colon (15:45). The conversion rules are identical.
Is midnight 0000 or 2400?
Both refer to the same instant, but 0000 is the standard: it marks the start of the new day. Some schedules use 2400 to mean the end of the previous day. Time clock and payroll systems almost always record midnight as 0000.
Free HR & payroll tips for small business
One short, useful email — wage-law changes, deadlines, and tools. No spam, unsubscribe anytime.
Keep reading
Track hours the easy way
Kloqk is a free time clock that handles punches, breaks, overtime, and payroll-ready reports.
Start free