Nursing and shift work · Study chart
Military time chart
The full 24-hour clock, hour by hour, with how to say each one; the rule for converting both ways; the times people look up most; how hospitals write times; and a typed practice drill. Free, no sign-up.
- All 24 hours
- Both-way rule
- 15 typed drills
- No sign-up needed
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Part 1 · The chart
The 24-hour clock, hour by hour
“Military time” is only the everyday name for the 24-hour clock: four digits, no colon, no AM or PM. The morning hours keep their number with a zero in front; from 1 PM on, the hour is 12 more. The minutes never change, so 1530 is 3:30 PM.
Military time chart (24-hour clock) · CollegeCompass360 free study tools
PM: add 12 to the hour. 12 AM → 00, 12 PM → 12. Midnight 0000, noon 1200. For study only. Sources: Open RN, Military Time; NIST, Times of Day FAQs.
| Standard | 24-hour | Said aloud |
|---|---|---|
| 12:00 AMMidnight, the start of the day | 0000 | midnight |
| 1:00 AM | 0100 | zero one hundred |
| 2:00 AM | 0200 | zero two hundred |
| 3:00 AM | 0300 | zero three hundred |
| 4:00 AM | 0400 | zero four hundred |
| 5:00 AM | 0500 | zero five hundred |
| 6:00 AM | 0600 | zero six hundred |
| 7:00 AM | 0700 | zero seven hundred |
| 8:00 AM | 0800 | zero eight hundred |
| 9:00 AM | 0900 | zero nine hundred |
| 10:00 AM | 1000 | ten hundred |
| 11:00 AM | 1100 | eleven hundred |
| Standard | 24-hour | Said aloud |
|---|---|---|
| 12:00 PMNoon | 1200 | twelve hundred |
| 1:00 PM | 1300 | thirteen hundred |
| 2:00 PM | 1400 | fourteen hundred |
| 3:00 PM | 1500 | fifteen hundred |
| 4:00 PM | 1600 | sixteen hundred |
| 5:00 PM | 1700 | seventeen hundred |
| 6:00 PM | 1800 | eighteen hundred |
| 7:00 PM | 1900 | nineteen hundred |
| 8:00 PM | 2000 | twenty hundred |
| 9:00 PM | 2100 | twenty-one hundred |
| 10:00 PM | 2200 | twenty-two hundred |
| 11:00 PM | 2300 | twenty-three hundred |
- Minutes stay as they are: 0630 is 6:30 AM, 1345 is 1:45 PM, 2359 is 11:59 PM.
- Leading zeros are written and spoken: 0600 is “zero six hundred”, 0005 is “zero zero zero five”.
- Midnight at the start of a day is 0000, said “midnight”. NIST writes 2400 only for the end of a day; some style guides discourage 2400 and write a time near midnight as 2359 or 0001.
Part 2 · Common lookups
What time is 1500? 1900? 2200?
The times people look up most, each with the one line of working. Every afternoon and evening hour is the standard hour plus 12.
What time is 1500?
1500is3:00 PM
Said “fifteen hundred”
15 is past 12, so take 12 away: 3 in the afternoon. A 3 PM vital-signs check is charted 1500.
What time is 1900?
1900is7:00 PM
Said “nineteen hundred”
19 − 12 = 7, so 1900 is 7 in the evening. A dose due at 7 PM reads 1900 on the administration record.
What time is 2200?
2200is10:00 PM
Said “twenty-two hundred”
22 − 12 = 10, so 2200 is 10 at night.
What time is 1330?
1330is1:30 PM
Said “thirteen thirty”
13 − 12 = 1, and the minutes stay as they are: 1:30 in the afternoon.
What time is 0600?
0600is6:00 AM
Said “zero six hundred”
Under 12, so the hour is the same: 6 in the morning. The leading zero is written and spoken.
What time is 1700?
1700is5:00 PM
Said “seventeen hundred”
17 − 12 = 5, so 1700 is 5 in the afternoon.
What time is 1600?
1600is4:00 PM
Said “sixteen hundred”
16 − 12 = 4, so 1600 is 4 in the afternoon.
What time is 1400?
1400is2:00 PM
Said “fourteen hundred”
14 − 12 = 2, so 1400 is 2 in the afternoon.
What time is 1800?
1800is6:00 PM
Said “eighteen hundred”
18 − 12 = 6, so 1800 is 6 in the evening.
What time is 2100?
2100is9:00 PM
Said “twenty-one hundred”
21 − 12 = 9, so 2100 is 9 at night.
What time is 1200?
1200is12:00 PM
Said “twelve hundred”
Noon. The hour stays 12 and the day switches to PM. Any time from 1200 to 1259 is a PM time with the hour 12.
What time is 0000?
0000is12:00 AM
Said “midnight”
Midnight, the first minute of the day. The hour 12 AM becomes 00, so 12:30 AM is 0030. NIST writes 2400 only for the end of a day.
Part 3 · The rule
Converting both ways
Two short rule sets. The only hours that catch people are the 12s: the midnight hour becomes 00 and the noon hour stays 12.
Standard time to 24-hour
- The minutes never change; only the hour can. Drop the colon and the AM or PM, then apply the hour rule below.3:30 PM → hour 3 (PM), minutes 30 → 1530
- AM, 1:00 to 11:59: keep the hour. Put a zero in front of a single-digit hour so there are always four digits.6:30 AM → 0630
- PM, 1:00 to 11:59: add 12 to the hour.7:15 PM → 7 + 12 = 19 → 1915
- The midnight hour, 12:xx AM, becomes 00xx.12:00 AM → 0000 · 12:30 AM → 0030
- The noon hour, 12:xx PM, stays 12xx.12:00 PM → 1200 · 12:45 PM → 1245
24-hour to standard time
- 0000 to 0059 is the midnight hour: write 12, the minutes and AM.0015 → 12:15 AM
- 0100 to 1159: drop the leading zero, put the colon back, add AM.0630 → 6:30 AM
- 1200 to 1259 is the noon hour: keep 12, add PM.1230 → 12:30 PM
- 1300 to 2359: subtract 12 from the hour, add PM.1915 → 19 − 12 = 7 → 7:15 PM
A quick check
If the four digits start with 13 to 23, it is afternoon or evening: subtract 12. If they start with 00, it is the hour after midnight: 12 AM. If they start with 12, it is the hour after noon: 12 PM. Everything else is a morning time with its own number.
Part 4 · On the chart
How hospitals write times
What nursing documentation texts say about the 24-hour clock in the record. For study: your facility’s own documentation rules come first.
The 24-hour clock is the standard for medication times
Nursing texts teach the 24-hour clock for documentation and call it the standard way to write medication administration times. It cuts the AM/PM mix-up and helps avoid a scheduled dose being given twice. A medication due at 7 in the morning and 7 at night reads 0700 and 1900 on the administration record.
Four digits, no colon
On an administration record the time is four digits with no colon: 0700, 1330, 1900. Minutes always get two digits, and an hour before 10 keeps its leading zero (0600, never 600). You may also see the same time with the colon kept on a screen or printout (15:00); read it the same way.
Midnight is 0000, the start of the day
The chart writes midnight as 0000 and noon as 1200. NIST writes 0000 for midnight at the start of a day and 2400 for the end of one, and calls “12 a.m.” and “12 p.m.” ambiguous. Some style guides discourage 2400 altogether and write a time near midnight as 2359 or 0001. Follow your unit’s convention.
Time of the task, or time of the entry
A nursing documentation text says the date and time on a note are the time you write it, except for vital signs, medication administration and other procedures, where you record the time the task was done.
Part 5 · Practice drill
Type the time
Fifteen drills, both directions, in a fresh order each run. Type the answer, press Check, read the working, move on. Your result is free.
The bonus
A wallet chart, a timesheet chart and 20 more drills
Locked: enter your email in the box above to open it
- A wallet-size chart to print: all 24 hours on one panel, minutes-to-decimal on the other. Cut it out and keep it behind your badge.
- The shift-hours version: a minutes-to-decimal chart (1 to 60 minutes) for timesheets that total hours as decimals.
- 20 more typed drills, with the odd minutes and the midnight and noon hours, every answer explained.
More free study tools
For the same shift
Nurse report sheet and SBAR builderA printable report sheet for your unit, SBAR scripts and a Glasgow Coma Scale study card.Sources
Where these facts come from
Everything on this page is written in our own words from these public sources. Your facility’s documentation rules come first.
- Open RN, Military Time (Open Resources for Nursing, CC BY 4.0) · The conversion chart, the AM and PM rules, and why the 24-hour clock is the standard for medication times.
- NIST, Times of Day FAQs · Midnight as 0000 at the start of a day and 2400 at the end; why 12 a.m. and 12 p.m. are ambiguous.
- Documentation in Nursing, 1st Canadian edition: Principles of Documentation · Use the 24-hour clock; add or subtract 12 to convert; the time of the entry versus the time of the task.
- Wikipedia, 24-hour clock · The spoken form (leading zeros are spoken; ten hundred, twenty hundred), writing with no separator, and the style guides that discourage 24:00.
- Cornell Law School LII, 29 CFR 785.48: Use of time clocks · The rounding practice behind the minutes-to-decimal note in the bonus.
Questions
Common questions
3:00 PM. Any 24-hour time from 1300 to 2359 is an afternoon or evening time: subtract 12 from the hour and add PM. 15 − 12 = 3. It is said “fifteen hundred”.
7:00 PM (19 − 12 = 7). On a medication administration record a dose due at 7 in the evening is written 1900, and the same dose in the morning is 0700, which is why nursing texts call the 24-hour clock the standard for medication times.
The chart uses 0000: midnight as the first minute of the new day, so 12:30 AM is 0030. NIST writes 0000 for midnight at the start of a day and 2400 for the end of one, and says “12 a.m.” and “12 p.m.” are ambiguous and should not be used. Some style guides discourage 2400 altogether and write a time near midnight as 2359 or 0001. If your unit has a convention, follow it.
Because four digits with no AM or PM leave no doubt which half of the day is meant. Nursing texts teach the 24-hour clock for documentation and call it the standard way to write medication administration times: it cuts the AM/PM mix-up and helps avoid a scheduled dose being given twice.
On an administration record the time is four digits with no colon: 0700, 1330, 1900. Minutes always get two digits and an hour before 10 keeps its leading zero. You may see the same time with the colon kept on a screen or printout (15:00); it is the same 24-hour time, read the same way.
“Zero six hundred.” Leading zeros are spoken, the whole hours are said as hundreds (1000 is “ten hundred”, 2000 is “twenty hundred”), and the minutes follow the hour: 1330 is “thirteen thirty”, 0545 is “zero five forty-five”.
No. “Military time” is just the everyday American name for the 24-hour clock, which is the usual way to write time across most of the world and in medical documentation. This page is a study chart for anyone who reads or writes it: nurses, medical assistants, EMTs, shift workers.
The chart, the lookups, the rules, the charting notes and the 15 typed drills with your result are free with no sign-up. An email unlocks the bonus: a printable wallet chart, the minutes-to-decimal timesheet chart and 20 more drills.