Time Format Converter
Convert between 12-hour (AM/PM), 24-hour, and four-digit military time. Type 2 PM, 2:30pm, 14:30, 1430, noon, or midnight and get all three formats.
12-Hour vs 24-Hour Time: What Is the Difference?
The 12-hour clock splits the day into two cycles, AM (midnight to noon) and PM (noon to midnight). The 24-hour clock counts from 00:00 at midnight to 23:59 just before the next midnight, so it needs no AM or PM. Both describe the same moments, only the notation differs.
The 24-hour clock is the most commonly used time notation in the world and the one specified by ISO 8601, the international date and time standard. The 12-hour clock is still the everyday written and spoken system in the UK, Ireland, the US, Canada outside Quebec, Australia, India, Mexico, Colombia, and the Philippines. In some European and Latin American countries people say the time in 12-hour form and write it in 24-hour form.
Even in 12-hour countries, fields where a mix-up is costly use the 24-hour clock: aviation, medicine, the military, and transport timetables. British Rail and London Transport, for example, switched their timetables to it in 1964.
The 12 AM and 12 PM Problem
12:00 AM is midnight, the start of the day, and 12:00 PM is noon. Nothing about the abbreviations makes that obvious, which is why many style guides, including The American Heritage Dictionary, The Canadian Press Stylebook, and NIST, advise against writing 12 AM or 12 PM at all. They recommend "noon" and "midnight", or 11:59 PM and 12:01 AM when you need an exact minute.
Midnight also has two 24-hour spellings. 00:00 is the start of a date. ISO 8601 also allows 24:00 for the end of a date, which is the same moment as 00:00 the next day. Some style guides and military rules discourage 24:00, so when you schedule something at midnight, write the date too, for example "00:00 on 2 October".
This converter accepts "noon", "midnight", and 24:00, and adds a one-line note whenever your time is one of these edge cases.
How to Convert Manually
12h to 24h: for AM times the hour stays the same, except 12:xx AM becomes 00:xx. For PM times add 12 to the hour, except 12:xx PM stays 12:xx.
24h to 12h: hours 00 to 11 are AM, and 00 is written as 12. Hours 12 to 23 are PM: subtract 12 from hours 13 to 23, and 12 stays 12. A quick check for PM hours is that the 24-hour number minus 12 should give the 12-hour number.
24-Hour Reference Chart
Every hour of the day in all three notations, on the hour. For minutes, keep the same minutes and only convert the hour.
| 24-hour | 12-hour | Military | Note |
|---|---|---|---|
| 00:00 | 12:00 AM | 0000 | Midnight, start of the day |
| 01:00 | 1:00 AM | 0100 | |
| 02:00 | 2:00 AM | 0200 | |
| 03:00 | 3:00 AM | 0300 | |
| 04:00 | 4:00 AM | 0400 | |
| 05:00 | 5:00 AM | 0500 | |
| 06:00 | 6:00 AM | 0600 | |
| 07:00 | 7:00 AM | 0700 | |
| 08:00 | 8:00 AM | 0800 | |
| 09:00 | 9:00 AM | 0900 | |
| 10:00 | 10:00 AM | 1000 | |
| 11:00 | 11:00 AM | 1100 | |
| 12:00 | 12:00 PM | 1200 | Noon |
| 13:00 | 1:00 PM | 1300 | |
| 14:00 | 2:00 PM | 1400 | |
| 15:00 | 3:00 PM | 1500 | |
| 16:00 | 4:00 PM | 1600 | |
| 17:00 | 5:00 PM | 1700 | |
| 18:00 | 6:00 PM | 1800 | |
| 19:00 | 7:00 PM | 1900 | |
| 20:00 | 8:00 PM | 2000 | |
| 21:00 | 9:00 PM | 2100 | |
| 22:00 | 10:00 PM | 2200 | |
| 23:00 | 11:00 PM | 2300 |
Military Time: Written and Spoken
Military time is the 24-hour clock written as four digits with no colon. 08:30 becomes 0830 and 14:00 becomes 1400. It is used by militaries and emergency services and, in aviation, together with UTC, where it is called Zulu time.
The spoken rules are specific. The leading zero is said out loud, so 0543 is "zero five forty-three". An exact hour uses "hundred" and never "thousand", so 0800 is "zero eight hundred" and 2000 is "twenty hundred". The 24-hour numbers already remove the AM and PM mix-up, and the spoken forms keep every digit clear over a radio or phone.
For a full 0000 to 2359 chart and pronunciation help, use the Military Time Converter.
Common Conversion Mistakes to Avoid
Swapping 12 AM and 12 PM. Midnight is 12 AM and 00:00. Noon is 12 PM and 12:00. Hour 12 is the one place both usual rules break: 12 AM is 00, not 12, and 12 PM stays 12 instead of becoming 24.
Leaving off AM or PM. A bare "9:30" could be morning or evening. In a 12-hour context always add AM or PM, or write 09:30 or 21:30.
Mixing up 24:00 and 00:00. They are the same moment but belong to different dates: 24:00 on 1 October is 00:00 on 2 October. For a deadline or a booking, name the date as well.
Treating a format change as a time zone change. Converting 3 PM to 15:00 does not change the moment, it only changes how it is written. To find what 3 PM is in another city, use the Time Zone Converter.
Frequently Asked Questions
How do I convert 12-hour time to 24-hour time?
For AM times, the hour stays the same except 12 AM, which becomes 00. For PM times, add 12 to the hour, except 12 PM, which stays 12. Examples: 1:30 AM is 01:30, 12:00 AM is 00:00, 2:45 PM is 14:45, and 12:00 PM is 12:00.
How do I convert 24-hour time to 12-hour time?
Hours 00 to 11 are AM, and 00 is written as 12. Hours 12 to 23 are PM, and you subtract 12 from hours 13 to 23 (12 stays 12). Examples: 00:00 is 12:00 AM, 09:30 is 9:30 AM, 13:00 is 1:00 PM, and 23:45 is 11:45 PM.
Is 12:00 AM midnight or noon?
Midnight. 12:00 AM is the start of the day and 12:00 PM is noon. Because this is so easy to mix up, several style guides, including NIST's, recommend writing "noon" and "midnight" instead, or using 11:59 PM and 12:01 AM when you need to be exact. This converter accepts the words noon and midnight as input.
Does 24:00 exist?
Under ISO 8601, 24:00 is allowed and means the end of a day, which is the same moment as 00:00 the next day. Some style guides and military rules discourage it and prefer 23:59 or 00:01. The converter accepts 24:00 and shows it as 00:00 (12:00 AM) with a note.
What is military time?
Military time is the 24-hour clock written as four digits with no colon: 0800 is 8 AM, 1430 is 2:30 PM, and 2359 is 11:59 PM. The only difference from 24-hour notation is the format. It is also spoken differently: the leading zero is said out loud, so 0543 is "zero five forty-three", and an exact hour uses "hundred", so 2000 is "twenty hundred".
Which countries use 24-hour time?
The 24-hour clock is the most widely used notation in the world and is the one in ISO 8601. In most countries it is the standard, especially in writing. The 12-hour clock is the dominant written and spoken system in the UK, Ireland, the US, Canada outside Quebec, Australia, India, Mexico, Colombia, and the Philippines, and some countries speak in 12-hour time but write in 24-hour time. Even where 12-hour time dominates, medicine, aviation, the military, and transport timetables use the 24-hour clock.
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What Is ISO 8601?
The standard that writes times in 24-hour form