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Military Time on a Timesheet: How to Read It and Total It

By Frame Sixty Labs · Last updated: September 11, 2026

What is military time, and why do timesheets use it?

Military time is the 24-hour clock written as four digits with no colon and no am or pm: 0645, 1730, 2200. Midnight starts the count at 0000 and the day ends at 2359, so every minute has exactly one name.

That single property is the whole reason time cards use it. On a 12-hour clock, 7:00 written in a hurry could be the start of a day shift or the start of a night shift, and a missing "pm" moves a punch by twelve hours. On a 24-hour clock, 0700 and 1900 cannot be mistaken for each other. Hospitals, airlines, transport, security and the armed forces all use it for that reason, and their timesheets follow.

The catch is that it trades one kind of error for another. Nobody writes down the wrong half of the day any more — but a four-digit number that looks a lot like a decimal starts inviting people to treat it like one. That is the real subject of this guide.

How do you convert military time to a 12-hour clock?

Two rules cover the entire day, and the minutes never change:

• 0100–1159: drop the leading zero, add am. 0645 is 6:45 am.
• 1300–2359: subtract 12 from the hour, add pm. 1445 is 2:45 pm, because 14 − 12 = 2.

The only awkward pair is the two twelves. 0000 is 12:00 am, midnight; 1200 is 12:00 pm, noon. Going the other way, add 12 to any pm hour: 6:30 pm is 18:30, so 1830.

How do you calculate hours worked from military time?

The 24-hour clock changes how the punches are written, not how they are subtracted. Minutes still run to 60, so you still borrow 60 — never 100. Take Monday: in at 0645, out at 1515.

1. Write both punches as four digits. 1515 and 0645, lined up.
2. Add 24 to the end time if the shift crossed midnight. It did not here, so nothing to do. More on this in the next section.
3. Subtract the minutes, borrowing 60. 15 − 45 will not go, so borrow one hour: 15 minutes becomes 75 minutes, and 75 − 45 = 30.
4. Subtract the hours. The 15 became 14 when you borrowed, so 14 − 6 = 8. The shift is 8:30.
5. Take the unpaid break off that shift. A 30-minute unpaid meal period makes it 8:00 worked.
6. Total the week in H:MM, then convert once. Carry every 60 minutes into an hour as you add, and only go decimal at the end.

Step 3 is where almost every manual error lives, and it is the same borrowing covered in how to subtract time in hours and minutes. Step 5 matters more than it looks: breaks come off the shift they happened in, not off the weekly total — see paid vs unpaid breaks on a timesheet.

What about shifts that cross midnight?

If the end punch is a smaller number than the start punch, the shift ran into the next day. A plain subtraction would give you a negative answer, so add 24 hours to the end time first.

Wednesday: in at 2200, out at 0630. Treat the 0630 as 3030, then subtract: 30:30 − 22:00 = 8:30. Take off the 30-minute break and the day is 8:00 worked.

If adding 24 to a clock time feels strange, split the shift at midnight instead and add the halves. 2200 to 2400 is 2 hours; 0000 to 0630 is 6 hours 30 minutes; together that is 8:30. Same answer, and it is a useful check.

One thing not to do is cap the day at 24 hours or quietly assume an 8-hour shift when the numbers look odd. Night shifts, on-call callbacks and doubles can legitimately produce long elapsed times. There is more on which workday a night shift belongs to in the overnight and overtime hours guide.

Why is 1445 not 14.45 hours?

Because a punch is a point in time and decimal hours measure a duration. They are different kinds of number, and 1445 is not a quantity of hours at all — it is a quarter to three in the afternoon. It is neither 14.45 hours nor 14.75 hours, because until you subtract two punches there is no duration to convert.

Here is what happens when the distinction gets lost. Monday was 0645 to 1515. Typed into an ordinary calculator as decimals:

The calculator's 8.70 overstates a single day by 0.20 hours — twelve minutes — because it borrowed 100 where it should have borrowed 60. And on Wednesday the same approach collapses entirely: 6.30 − 22.00 is −15.70, a number with no meaning on a timesheet.

This is the same base-10 versus base-60 problem described in why your phone's calculator can't add time. A 24-hour clock just makes the bad input look more plausible, because 15.15 reads like a perfectly ordinary decimal.

A full week on the 24-hour clock

A five-day week with two night shifts and a short Friday, at $24.00 an hour, with a 30-minute unpaid meal period on every shift over eight hours.

Adding the worked column in H:MM: 8:00 + 10:00 = 18:00, + 8:00 = 26:00, + 7:45 = 33:45, + 4:30 = 38:15. The minute check agrees: 480 + 600 + 480 + 465 + 270 = 2,295 minutes, and 2,295 ÷ 60 = 38.25 hours.

Note what the last step did not produce. The week is 38:15 in H:MM and 38.25 in decimal — not 38.15. Fifteen minutes is a quarter of an hour, so it converts to .25. Paid at $24.00:

• Correct: 38.25 × $24.00 = $918.00
• Misread as 38.15: 38.15 × $24.00 = $915.60
• Difference: $2.40 a week, roughly $124.80 over 52 weeks

Small per week, and invisible unless someone checks. The fix is a habit rather than a formula: keep everything in H:MM while you are entering it, and convert exactly once, at the end. Converting each day first rounds five times instead of once — the reasoning is in hours to decimal: every conversion explained.

Is midnight 0000 or 2400?

Both, depending on which side of it you are standing. 0000 is midnight as the start of a day; 2400 is midnight as the end of the day before. They are the same instant with two names.

On a timesheet the distinction is genuinely useful. A shift that finishes at midnight is cleanest written as ending 2400, because that keeps the whole shift on the day it started. A shift that begins at midnight starts at 0000 on the new day. Written the other way round, an eight-hour shift can end up split across two rows, or filed under a day nobody worked.

Frequently asked questions

What is military time?

The 24-hour clock written as four digits with no colon and no am or pm, such as 0645 or 1730. Hours run 00 at midnight through 23 at 11 pm, so every minute of the day has exactly one name — which is why healthcare, aviation, transport and security timesheets use it.

How do you convert military time to a 12-hour clock?

From 1300 to 2359, subtract 12 from the hour and add pm: 1445 is 2:45 pm. From 0100 to 1159, drop the leading zero and add am. The two special cases are 0000 = 12:00 am (midnight) and 1200 = 12:00 pm (noon). Minutes never change.

Is 1445 the same as 14.45 hours?

No. 1445 is a point in time — 2:45 pm — not a duration, so it is neither 14.45 nor 14.75 hours. Decimal hours describe how long something lasted, and you only get a duration after subtracting two punches.

How do you calculate hours worked from military time?

Subtract start from end, borrowing 60 minutes rather than 100. For 0645 to 1515: 15 minutes becomes 75, 75 − 45 = 30, and 14 − 6 = 8, giving 8:30. Then take any unpaid break off that shift.

How do you handle a shift that crosses midnight?

Add 24 hours to the end time. For 2200 to 0630, treat the end as 3030, and 30:30 − 22:00 = 8:30. Splitting at midnight gives the same answer: 2 hours before, 6:30 after.

Is midnight 0000 or 2400?

Both — 0000 is midnight starting a day, 2400 is midnight ending the previous one. On a time card, end a shift at 2400 and start one at 0000, so each shift stays attached to the day it belongs to.

Does military time use a colon?

Strict military style does not: 1445, often spoken as "fourteen forty-five hours". The international 24-hour convention that payroll software and phone settings use writes 14:45. Same clock, same time. What matters on a timesheet is keeping the leading zero.

Why is a 38:15 week not 38.15 hours?

The part after the separator is minutes out of 60, not hundredths, so 38:15 is 38.25 decimal. At $24.00 an hour that is $918.00 against $915.60 — $2.40 a week, about $124.80 a year.