Military Time – History and Explanation. Have you ever watched a war or military movie and wondered why they say the time so differently than the rest of the population? Instead of three o’clock, it’s either “0 300 hours” or “1500 hours” depending on whether it’s 3AM or 3PM. This may seem odd, but there’s a reason and a history behind military time.
The History of Military Time
Military time actually dates back to the Egyptian astronomical system of decans. Astronomers, scientists, horologist and navigators all have used military time or the 24-hour time system for thousands of years. In fact, some very famous clocks were built with the 24-hour system including the Shepherd Gate Clock found in Greenwich and the Orloj in Prague.
Italy’s first mechanical public clocks were all built on the 24-hour time system. However, since these clocks required a large amount of rope and the mechanism tended to wear out quickly, they were switches to a different system. On the 24-hour system 300 strokes were required every single day. When this was switched to a 1 through 12 or even a 1 through 6 (repeated 4 times) system, it cut the strokes down to 156 and 84 respectively.
A report from the London Times dating back to 1886 also shows the 24-hour clock being used. It was used at Port Arthur on the Canadian Pacific Railway. Italy was the first country to use the 24-hour time across their nation, which happened in 1893. Many other European countries followed and some in Latin America even adopted the 24-hour clock.
The first documented use of the 24-hour time system in the military came in 1915 when the British Royal Navy and Allied armed forces adopted the use of what we know as Military Time today. The British Army switched to military time in 1918 and the US Navy make the change in 1920. It wasn’t until July 1, 1942 that the US Army adopted the 24-hour time clock, however.
What is Military Time?
The phrase “Military Time” refers to a 24-hour clock system, which used to be the way time was kept in many parts of the work. This system of keeping time is very popular throughout the branches of military of the world and has been used by the United States Armed Forces for many years.
Instead of keeping time based on 12-hour increments running from 1am to 12pm (noon) and from 1pm to 12am (midnight), military time uses a system running from 1 to 23. For example, instead of 3:00pm, military time uses 15:00 with no need for pm.
While military time is a 24-hour clock system, it does have some differences compared to other 24-hour time systems. For example, the military doesn’t use any type of separator when writing the time and the leading zeros are written out and spoken. A letter is also used at the end of the time to denote the time zone. If a J or “Juliet” is used, it denotes local time.
While military time may seem odd to civilians, it’s common to those within the military. It’s one of the first adjustments new recruits learn to make and it’s not hard to learn.