What is a 24-Hour Clock? Learn Convert and Read 24-Hour Time

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24-Hour Clock is a worldwide used time format. Most of the people are wondering how this time format works and how to use it. You should know there are two types of time formats. One is the 24-Hour Time Format and the other one is 12-Hour Time Format. Find below a short but concise answer what 24-Hour Clock is:

The 24-Hour Clock is a Time format where you don’t use AM and PM. Counting for the first 12 hours of the day is the same as in 12-Hour Clock but then hours counting continue from 13 to 24 for PM hours. 24-Hours Time format is also known as Military Time.

This article describes how 24-Hour Clock works and what are the main differences between this Time Format and 12-Hour Clock or Military Time. You also learn how to convert, read and write 24-Hour Time. So sit back and continue reading.

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What is a 24-Hour Clock?

The 24 Hour Clock is a method of time telling that goes from Midnight to Midnight, divided into 24 hours and is indicated by the number of hours passed from Midnight, or 0 to 23.

And this is how 24-Hours Clock looks like:

Military Time clock - 24 hours format

TIP: Are you surprised that 24-Hour Format Clock contains all 24 hours on the clock face? In fact, this is a real clock so if you like them, you can buy them here.

The term Military Time is actually a synonym for the 24-hour clock. But what’s funny is this is only largely popular in the United States and Canada because the customary 12 hour time with am/pm suffixes is considered dangerous in many professions.

The most notorious obviously being the military, thus how the 24 hour time clock got its nickname. In most other places in the world, you will commonly see the 24-hour clock as a standard practice.

TIP: In case you want to understand how to make the conversion from 24-hours time format (military time) to 12-hour time format (civilian time) for specific times check out our posts with an explanation for the specific military time conversions.

Specific military time conversions with explanation

24-Hour Time Conversion Chart

You can easily convert any time from 24-hour time format to 12-hour time format with this simple conversion chart:

24-Hour Clock Conversion Chart

24-Hour Clock 12-Hour Clock
00:00 Hours 12:00 AM
01:00 Hours 1:00 AM
02:00 Hours 2:00 AM
03:00 Hours 3:00 AM
04:00 Hours 4:00 AM
05:00 Hours 5:00 AM
06:00 Hours 6:00 AM
07:00 Hours 7:00 AM
08:00 Hours 8:00 AM
09:00 Hours 9:00 AM
10:00 Hours 10:00 AM
11:00 Hours 11:00 AM
12:00 Hours 12:00 PM
13:00 Hours 1:00 PM
14:00 Hours 2:00 PM
15:00 Hours 3:00 PM
16:00 Hours 4:00 PM
17:00 Hours 5:00 PM
18:00 Hours 6:00 PM
19:00 Hours 7:00 PM
20:00 Hours 8:00 PM
21:00 Hours 9:00 PM
22:00 Hours 10:00 PM
23:00 Hours 11:00 PM
24:00 Hours 12:00 AM

If you are interested in how similar chart looks like for half hours or different minutes, visit this comprehensive article:

Military Time Chart: Fastest Way to Convert Military Time

Difference between 24-Hour Time vs 12-Hour Time

It is important that you learn the difference between the 12-hour and 24-hour time format.

The main difference is that there is no AM and PM in the 24-hour time format. However, in 12-hour format, there is confusion because 12 hours are repeated twice in a day.

This illustration explains to you how to deal with missing AM and PM:

Differencies between standard time and military time - short explanation

As you can see, 24-hour time uses numbers from 13 to 24 for PM hours in standard time.

However, the civilians have to deal with understanding AM and PM of the time. This distribution of the time during the day can be confusing. For example, you set up your alarm clock to 7:00 PM instead of 7:00 AM.

But when you use the 24-hour time format, you don’t make this mistake because 7:00 PM is written as 1900 hours. So you can see, there is no space for mistakes with using the 24-hour clock.

To better understanding of the difference between 12-hour and 24-hour time format, watch this short but useful video:

Difference between 24-Hour Time vs Military Time

Both these time formats use the 24-hour time format. There are 2 main differences between them:

  • Military Time doesn’t use colons between hours and minutes. For example, 2:00 PM is written as 1400 in Military Time and 14:00 in 24-Hour Time.
  • 24-Hour time doesn’t have to use (but it can) leading zero for hours from 0 to 9. For example, 2:00 AM is written as 0200 in Military Time and 2:00 in 24-Hour Time.

On the other hand, other features have in common. First of all, neither of them uses AM or PM.

Where is 24-Hour Clock being used?

This is by far the most widely used time telling system in the entire world, yet in many places around the globe, you will still find many people using the conventional 12-hour clock.

It is easier to list countries where the 24-Hour Clock isn’t used:

12-Hour Time Format is used in the United States, Philippines, Canada, Australia, New Zealand, India, Egypt, Saudi Arabia, Columbia, Pakistan, and Malaysia.

On the other hand, some professions in these countries use 24-Hour Clock. They are soldiers, pilots or emergency services.

How does 24-Hour Clock Work?

A common question that most people ask is how 24-hour clock works. They want to learn the 24-hour time format. It will help them to deal with the conversion.

They will not have to deal with confusion when both time formats come in front of them. Here are a few things you need to know about the 24-hour time.

In 24 hour time, the day always begins at 00:00 and the last minute of every day begins at 23:59. However, when it is appropriate, the expression 24:00 is used to describe the end of the beginning of the day. Just keep in mind that 00:00 and 24:00 are the exact same time when referring to 24-hour time notation.

With that said, 24:00 is mainly used to refer to the exact end of a day or time interval like store hours. Typical store hours could read something like: “open 9:00 to 24:00″ and that would the store is open from 9:00 AM to Midnight. Whereas “Zero” or “00:00″, in this case, would confuse people instead of helping them understand the store’s hours of operation.

A lot of times when a police officer takes a report and the person says the event happened at Midnight, the officer will always put down 23:59 or 00:01 to avoid confusion when the time is converted to 12 hours time later.

How to Convert 24 Hour Time?

Converting 24-Hour Clock isn’t as difficult as it looks. All you need to do is to follow these simple rules:

  • Time from 0000 to 1159 means AM
  • Time from 1200 to 2400 means PM
  • 0000 and 2400 is midnight and have the same meaning

For the time from 0001 to 1259, you don’t need to subtract 12 hours. Then for the time from 0001 to 1159, you just add AM and for the time from 1200 to 1259, you add PM.

When you see the time from 1300 to 2359, you have to subtract 12 hours from the seem time and add PM. For example, 2230 hours is 10:30 PM in standard time.

It can take some time to learn how to convert these two time formats, and that’s the reason why I created simple and useful online tools that help you to convert any time you want online.

So another option for converting a given time is to use these online converters. They will allow you to quickly convert the time so that you will not have to waste your time.

Converter from Military Time to Normal Time

Convert Military Time to Standard Time
Standard Time:

Converter from Normal Time to Military Time

Convert Standard time to Military Time
Military Time:

In the case, you are still not familiar with converting 24-hour time format, you can read this article that definitely helps you:

How to Convert Military Time? Use Military Time Converter

How to Read 24-Hour Time Format?

As you already know, the 24-hour clock contains four digits where the first two digits belong to hours and the second ones belong to minutes.

This table below explains to you how to read the full hours:

24-Hour Clock How to Read
00:00 Hours Zero-zero-zero-zero
01:00 Hours Zero one hundred hours
02:00 Hours Zero two hundred hours
03:00 Hours Zero three hundred hours
04:00 Hours Zero four hundred hours
05:00 Hours Zero five hundred hours
06:00 Hours Zero six hundred hours
07:00 Hours Zero seven hundred hours
08:00 Hours Zero eight hundred hours
09:00 Hours Zero nine hundred hours
10:00 Hours Ten hundred hours
11:00 Hours Eleven hundred hours
12:00 Hours Twelve hundred hours
13:00 Hours Thirteen hundred hours
14:00 Hours Fourteen hundred hours
15:00 Hours Fifteen hundred hours
16:00 Hours Sixteen hundred hours
17:00 Hours Seventeen hundred hours
18:00 Hours Eighteen hundred hours
19:00 Hours Nineteen hundred hours
20:00 Hours Twenty hundred hours
21:00 Hours Twenty-one hundred hours
22:00 Hours Twenty-two hundred hours
23:00 Hours Twenty-three hundred hours
24:00 Hours Twenty-four hundred hours

TIP: For times from 0 to 9 hours and minutes from 0 to 9 is common to read leading zero as “Oh” instead of “Zero”. For example, 0405 Hours is read as “Oh Four Oh Five Hours”.

You can learn more about reading Military Time from this article:

How to Read Military Time? Simple Explanation with Examples

How to Write 24-Hour Time Format?

You may have already figured out how to write a 24-hour time format by reading this post. But if not, you don’t need to worry, I explain to you in this section.

The complete structure of the 24-hour time format is:

hours (colon) minutes (colon) seconds

The most used writing format is without seconds but you should also know how to write the time with them. Because you can see the format with seconds in many public places. So by knowing the complete structure, you won’t get confused when you see it somewhere.

To better understanding, you can find some examples down below:

A time of day written in the 24 hour time is generally expressed like this: 1543 and would be spoken as “fifteen forty three”.

However, there are many different variations as to how time can be expressed. Sometimes, you’ll commonly see a colon inserted into the time to break the hours from the minutes, like this: 15:43.

A leading zero is often expressed in 24 hour time that is less than 10 hours. The zero is most commonly used when telling military time, like this: 0312 and would be spoken as “zero three hundred twelve hours” or “oh three hundred twelve hours”.

You can also see the time in 24-hour time format without leading zero for hours that are less than 10. For example, in 4:51. This time would be spoken as “four fifty one hours”.


I know that the 24-hour clock can confuse you sometimes. But I hope this post helped to understand what the 24-hour clock is and how to use and convert this time format.

To remind you, here are the most important facts about the 24-hour clock time format:

  • Hours don’t repeat twice a day in this time format
  • The 24-hour clock doesn’t use AM and PM
  • AM hours are the same in 24-hour time format as in 12-hour time format and are counting from 0 to 12
  • PM hours are different, they are counting from 13 to 24
  • The 24-hour clock contains four digits, the first two digits belong to hours and the second ones to minutes
  • The minutes are always the same in both time formats
  • Synonym for 24-hour time is Military Time

This knowledge helps with the understanding of 24-hour time and its conversions. If math is not your strength, you can use time converters from this website. These converters help you convert any time you want immediately.

If you are still interested in topics related to Military Time feel free to visit other articles in the categories below:

Military Time Tools

About Military Time

Military Time Conversions

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