Understanding the 24-Hour Clock

The 24-hour method of time keeping has been used for centuries. In 1917, the British and Canadian military began to use the 24-hour clock to clarify orders and communications in relation to published orders or when the order should be carried out. The 24-hour clock has been known as railway time in most of Europe and continental time in England. In the United States, it is best known as military time. Most of the world uses the 24-hour clock as part of their daily routine. In the US military, the 24-hour clock allows for precision in military operations and allows that same precision to be coordinated with other militaries. When it comes to military operations, the coordination within the military must not be confused in relation to the time zone the individual units are in. To keep military operations in sync, Zulu time is used. Zulu time (known as Greenwich Mean Time) is the same, everywhere. Each time zone around the world has a letter assigned to the zone. The letter Z identifies the time zone in Greenwich, England. Since military organization could be in several time zones around the world, Zulu time allows for exact timing of any event anywhere in the world. Since there are 24 time zones around the world, Zulu time is universally understood and is used to ensure clear and effective communications anywhere on the planet. Let us now look at how the 24-hour clock is used.

Today, many clocks and watches have the ability to use either the 12 or 24-hour clock display. Using the 24-hour clock is really simple, once some basic principles are understood. Understand there are 24-hours in a day. The day begins at 0000 and ends at 2400 (or 12 am to 12 pm). As the day progresses, time is simply counted up as the hours pass. At 12 noon, the time would be 1200 and half the day has passed. At 2 pm, the time would be 1400 on the 24-hour clock. To simplify this, please review the included chart. Typically, 12 midnight is described as 2400, the end of the day. The beginning of the next day would be indicated as 0001, or one minute after midnight. For example, if you worked from 9am until 5pm, your work hours would be 0900 to 1700. If we’re going to meet someone for coffee at 7…is that am or pm? If you set your coffee date for 1900, you would instantly know to be there at 7 pm. Using the 24-hour clock will reduce confusion.

So why use 24-hour clock? As stated, most of the world uses it. It is used in the US trucking, railroad, medical, police, fire and travel industries just to name a few. Anywhere time must be precise; you will find the use of the 24-hour clock. If you travel around the world, you will find the 24-hour clock used to clarify a specific time of day. There is no need to buy a 24-hour clock, just practice with the chart and any clock can be a 24-hour clock.

We described what the 24-hour clock method was and how it is used. We know most industry which has a need for precise time, without confusion, uses the 24-hour clock. We also learned that most of the world uses the 24-hour clock in their daily routine. Using the provided chart and practice can allow you to convert time effortlessly. Don’t be confused when traveling abroad; learn to use the 24-hour clock.

24-hour Clock Conversion Chart

Morning Hours
0000 = 12 am (midnight)
0100 = 1 am
0200 = 2 am
0300 = 3 am
0400 = 4 am
0500 = 5 am
0600 = 6 am
0700 = 7 am
0800 = 8 am
0900 = 9 am
1000 = 10 am
1100 = 11 am

Evening Hours
1200 = 12 am (noon)
1300 = 1 pm
1400 = 2 pm
1500 = 3 pm
1600 = 4 pm
1700 = 5 pm
1800 = 6 pm
1900 = 7 pm
2000 = 8 pm
2100 = 9 pm
2200 = 10 pm
2300 = 11 pm
2400 = 12 pm (midnight)