Free 12-hour and 24-hour clock tool
Military Time Converter
Convert AM/PM time to four-digit military time or change a 24-hour clock reading back to 12-hour time. Handle noon, midnight, optional seconds and controlled 2400 notation.
Last Updated: July 25, 2026
Convert Military and Standard Time
Select a direction, enter one clock reading and review every equivalent format. This tool changes notation only. It does not change the represented time zone.
A military time converter changes a clock reading between the 12-hour AM/PM system and the 24-hour system. Enter 5:30 PM and the tool returns 17:30 or 1730 hours. Enter 1730 and it returns 5:30 PM. The represented moment stays the same. Only the written notation changes.
The calculator keeps noon, start-of-day midnight and end-of-day midnight separate. It accepts four-digit military time, colon-based 24-hour time and optional seconds. It also shows the time as minutes after midnight, the remaining duration to the next midnight and a transparent conversion audit.
How to Use the Military Time Converter
- Select 12-hour to military time when your input includes AM or PM.
- Enter an hour from 1 through 12 and a minute from 0 through 59.
- Enter a second only when you need six-digit precision. Leave the field blank for the usual four-digit result.
- Select AM or PM. Check this setting carefully because it changes most afternoon and evening hours by 12.
- Select Military time to 12-hour when your input is a 24-hour reading.
- Enter a compact value such as
1730or a colon value such as17:30. The tool also accepts730as0730. - Choose whether the exact value 2400 is accepted as an end-of-day marker.
- Select the convert button, then review the military, 24-hour and 12-hour outputs.
What Is Military Time?
Military time is a common name for writing time of day on a 24-hour clock. The hour runs forward from 00 after midnight through 23 before the next midnight. A four-digit form places two hour digits before two minute digits. For example, 06:45 becomes 0645 and 21:10 becomes 2110.
The 24-hour clock is broader than military use. Aviation, weather reporting, emergency services, hospitals, transport systems, computing and international schedules also use it. The ISO 8601 overview shows time in hour, minute and second order and gives 18:00:00 as a 6 PM example.
Writing a time in 24-hour form removes the AM/PM label. It does not identify a location. A value such as 1730 might be local time, UTC or another stated zone. Add the date and time-zone label when a schedule crosses places or requires an exact instant.
12-Hour to Military Time Formula
The conversion rule depends on the period and the 12-hour input hour. Minutes and seconds stay unchanged.
| 12-hour input | Hour operation | Military result |
|---|---|---|
| 12:20 AM | Replace hour 12 with 00 | 0020 hours |
| 7:05 AM | Keep 7 and pad it to 07 | 0705 hours |
| 12:40 PM | Keep hour 12 | 1240 hours |
| 5:30 PM | 5 + 12 = 17 | 1730 hours |
| 11:59 PM | 11 + 12 = 23 | 2359 hours |
Worked Example: Convert 5:30 PM to Military Time
Start with 5:30 PM. The hour is from 1 through 11 and the period is PM, so add 12 to the hour.
- Hour conversion: 5 + 12 = 17.
- Minute conversion: keep 30 unchanged.
- 24-hour clock result: 17:30.
- Remove the colon for common military notation: 1730 hours.
- Elapsed time after midnight: 17 hours 30 minutes, or 1,050 minutes.
- Time until the next midnight: 6 hours 30 minutes.
The result is not 0530 because that value means 5:30 AM. It is not 17.30 decimal hours either. The colon and compact four-digit forms both describe clock time, whose minute portion uses base 60.
Military Time to 12-Hour Formula
For the reverse conversion, inspect the two-digit 24-hour hour. Keep minutes and seconds unchanged.
For example, split 2145 into hour 21 and minute 45. Since 21 is greater than 12, subtract 12. The answer is 9:45 PM. A compact input must retain minute padding, so 2105 means 9:05 PM rather than 9:50 PM.
Military Time Conversion Chart
| 12-hour time | 24-hour clock | Military notation |
|---|---|---|
| 12:00 AM | 00:00 | 0000 hours |
| 1:00 AM | 01:00 | 0100 hours |
| 6:30 AM | 06:30 | 0630 hours |
| 11:59 AM | 11:59 | 1159 hours |
| 12:00 PM | 12:00 | 1200 hours |
| 1:00 PM | 13:00 | 1300 hours |
| 5:30 PM | 17:30 | 1730 hours |
| 9:45 PM | 21:45 | 2145 hours |
| 11:59 PM | 23:59 | 2359 hours |
0000 vs 2400 at Midnight
Both values are associated with midnight, but they attach to different sides of a date boundary. The value 0000 identifies the beginning of a day. The value 2400, when an organization permits it, identifies the end of a stated day and the same boundary instant as 0000 on the following date.
Rules differ by system. A Department of the Navy correspondence manual describes four-digit military time in a range ending at 2400. FAA surface-weather procedures instead state that 0000 and 2359 mark the beginning and ending of the day. A current NOAA Coast Pilot gives noon as 1200 and midnight as 0000.
This calculator makes the choice visible. When 2400 handling is enabled, it accepts only 2400, 24:00, 240000 or 24:00:00. It rejects 2401 and every other value after 24:00. When strict 0000 handling is selected, 2400 is rejected.
Four-Digit and Colon Formats
Military notation often removes the colon and uses exactly four digits. The first two digits identify the hour. The final two identify the minute. A leading zero keeps morning values aligned, so 7:30 AM is written 0730 rather than 730 in formal four-digit output.
A colon-based 24-hour clock writes the same time as 07:30. The converter accepts both forms. It also accepts a three-digit input such as 730 for convenience, then normalizes it to 0730. It does not accept ambiguous one-digit, two-digit or malformed values.
| Input form | Accepted meaning | Normalized output |
|---|---|---|
730 | Hour 7, minute 30 | 0730 or 07:30 |
0730 | Four-digit military time | 0730 or 07:30 |
7:30 | Colon-based 24-hour time | 0730 or 07:30 |
173045 | Hour 17, minute 30, second 45 | 173045 or 17:30:45 |
17:30:45 | 24-hour time with seconds | 173045 or 17:30:45 |
How Seconds Are Handled
Standard military time usually focuses on hour and minute. Some logs, technical systems and event records need seconds. In compact form, six digits use HHMMSS order. The input 173045 means 17 hours, 30 minutes and 45 seconds, which converts to 5:30:45 PM.
The optional second field preserves intent. If you leave it blank, the result stays four digits. If you enter zero, the converter shows a six-digit result ending in 00. Seconds must be whole numbers from 0 through 59. Leap seconds require a specialized time-scale tool, so 60 is not accepted.
Minutes After Midnight
The result includes elapsed minutes after the start of the day. This value helps with schedules, data validation and spreadsheet calculations. Convert the hour to minutes, then add the minute component.
For 17:30, multiply 17 by 60 to get 1,020, then add 30. The answer is 1,050 minutes. When seconds are present, the result card keeps them as a separate remainder. Under the accepted end-of-day convention, 2400 represents 1,440 minutes after the stated day's start.
The fixed unit relationships follow NIST Special Publication 330: one minute contains 60 seconds, one hour contains 60 minutes and one day contains 24 hours.
Military Time Does Not Automatically Mean UTC
A 24-hour format and a time zone answer different questions. The format controls how the clock reading is written. The time zone controls which location or global reference the reading belongs to. The same notation 1730 can mean 5:30 PM local time, 17:30 UTC or 17:30 in another named zone.
A trailing Z often identifies UTC in aviation and military contexts, but this converter does not add or remove Z. It does not infer a location, apply daylight-saving rules or shift a time. For cross-location work, record the date, time and named zone or UTC offset before performing a zone conversion.
Common Uses for a Military Clock Converter
- Read travel, aviation, shipping and emergency-service schedules.
- Prepare logs whose hour and minute fields must remain four digits.
- Convert hospital, security, dispatch and operations times.
- Check an AM/PM value before calculating an elapsed duration.
- Normalize clock readings before sorting them in a spreadsheet.
- Explain noon and midnight entries in a shared schedule.
- Convert a time with seconds without dropping the second component.
For a duration between two clock readings, use the Time Duration Calculator. For adding or subtracting elapsed quantities, use the Time Calculator. Conversion and duration are separate operations.
Common Military Time Conversion Errors
Adding 12 to noon
12:00 PM stays 12:00 and becomes 1200. Adding 12 would create 24:00, which is an end-of-day boundary rather than noon.
Leaving midnight as hour 12
12:00 AM becomes 00:00 and 0000 at the start of a day. Values from 12:01 AM through 12:59 AM also use hour 00.
Removing a leading zero
Formal military output normally keeps four digits. Write 0645 for 6:45 AM. A three-digit input is convenient, but the normalized result restores the zero.
Reading minutes as decimal fractions
1730 means hour 17 and minute 30. It does not mean 17.30 decimal hours. The clock value equals 17.5 decimal hours because 30 minutes is half an hour.
Assuming 2400 is accepted everywhere
Organizational rules vary. Use the calculator's strict setting when a system requires 0000 through 2359, and verify the destination format before submitting a formal record.
Forgetting the time zone
Changing 5:30 PM to 1730 does not move the time between locations. Add a zone label and use a dedicated zone converter when the actual instant must change.
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Frequently Asked Questions
What is military time?
Military time is a four-digit way to write time on a 24-hour clock. The first two digits show the hour from 00 through 23, and the last two show minutes from 00 through 59.
How do I convert PM time to military time?
For 1:00 PM through 11:59 PM, add 12 to the hour and keep the minutes. For example, 5:30 PM becomes 17:30 or 1730. Keep 12:00 PM through 12:59 PM as hour 12.
What is 12:00 AM in military time?
12:00 AM at the start of a day is 0000 hours. Times from 12:01 AM through 12:59 AM use hour 00, such as 0015 for 12:15 AM.
What is 12:00 PM in military time?
12:00 PM is 1200 hours. Noon keeps hour 12. Do not add 12, because 2400 refers to an end-of-day midnight convention rather than noon.
Is 2400 a valid military time?
Some organizations use 2400 for the exact end of a stated day, while others require 0000 at the next day's start and end the prior day at 2359. The calculator supports both rules and rejects values such as 2401.
Does military time use a colon?
Common four-digit military notation omits the colon, so 5:30 PM appears as 1730. A general 24-hour clock often uses 17:30. This calculator accepts and displays both forms.
What time is 1730 in standard time?
1730 is 5:30 PM. Split the value into hour 17 and minute 30, subtract 12 from hour 17, and attach PM.
Can military time include seconds?
Yes. A six-digit HHMMSS value includes seconds. For example, 173045 means 17:30:45, or 5:30:45 PM. This calculator accepts seconds from 00 through 59.
Does this converter change time zones?
No. It changes only the notation used for one clock reading. It does not infer UTC, local time, a geographic location, daylight-saving time or a calendar date.
Method and Sources
The conversion uses standard 12-hour and 24-hour clock rules. Format examples follow the ISO 8601 overview. Military notation and 2400 guidance are compared with the Department of the Navy correspondence manual, FAA surface-weather procedures and the NOAA Coast Pilot. Fixed hour, minute and second relationships follow NIST Special Publication 330.