Military time, also known as the 24-hour clock, can be confusing for many that learned how to tell time-based on a 12-hour system. Proponents of the 12-hour system argue that there is too much math involved with the 24-hour system and utilizing AM and PM to differentiate between day and night is just fine. However, there are many professionals and organizations that utilize the 24-hour format to tell time. While many countries still use the 12-hour clock, much of the population within those countries use military time. Military time is the system of time that counts from 0 (midnight) to 24 (midnight the following day).
Imagine, you’re sitting on a watch floor in Bahrain, monitoring your communications links, ensuring not a single unit or ship in your area of operations (AOR) loses the ability to communicate with the outside world. Communications in this AOR is incredibly important. The coordination of missile launches, logging ship or unit movement, keeping morale high, and allowing members of your unit to call home to their families are just some of the services your watch floor provides. Your space has no windows, it’s freezing cold, the air conditioning is on high to ensure none of your equipment overheats, you have no real way to see outside into your building’s surrounding area, and you feel like you’ve been sitting there forever watching your computer screen for any errors or drops of links. You ask your coworker to check the time, to see how much of your watch is left. They respond that it’s 2200, you have nine hours of watch left and only three hours have passed. However, 2200 tells you it’s night time, or in civilian time, 10:00 PM.
In the United States and in the English-speaking parts of Canada, Military time is synonymous with the 24-hour clock because it is strictly used in the Military and not by civilians. Military time does more than help watch floor standers tell what time of day it is. More often than not, the ability to give accurate timing for a military operation can predict the success or failure of a mission beyond the wire. During the Great War, now known as World War I, no military operation could afford any uncertainty regarding time. Much of the military world relies on precise timekeeping. Therefore, to reduce any ambiguity, improve strategic planning, and communication, the military adopted the 24-hour clock system. This way, there is no confusion between 12 noon and 12 midnight and no misperception of AM or PM.
The 24-hour system is used in various other industries such as aviation, science, and polar explorers. Pilots, while flying planes all over the world, time changes can be confusing in the 12-hour format. The use of 24 hours ensures that it is understood that when they say they will arrive at 1600Z, they mean that they will arrive at 4:00 PM Greenwich Mean Time. It shortens communications, allowing them to focus more at the job at hand. Polar explorers and scientists use the system because the Sun’s presence in that area of the world is so dependent on the season. In the winter, it is dark all day, while in the Summer, the Sun is present all day and night, giving the illusion of an ever-present day. This can be incredibly disorienting. Utilizing this method helps Polar explorers tell what time of day it is. Hospitals too, use the 24-hour time system to specify the time of day an operation occurs or when medicine is administered, as confusion for both operations and medicine administration could be life-threatening.
Origins Of The Military 24-Hour System
24-hour time began during the Early Egyptian era. Coffins had the Diagonal Star Table painted on the inner lid. These were found in tombs dating back to 2100 BC, approximately the end of the First Intermediate Period and the beginning of the New Kingdom during the 11th dynasty. At the time, there were many different time systems used around the world, however, Egyptians synchronized with the celestial bodies as they passed through the sky. The resulting tables are regarded as the first human attempt to model the motion of the stars with an elegant linear model. The patterns were used to define the vague Egyptian year, leading to the assumption that the tables were used as time-keeping devices. Eventually, this led to a year with 360 days. Unlike our current 60-minute hour, Egyptians used temporal hours which divided the daylight hours into an equal number of hours based on the intensity of the sun during different seasons, resulting in long days during the Summer and short days during the Winter. Below is a picture of an Egyptian coffin lid, depicting the Diagonal Star Table.
Around the 14th century, the method for counting hours transitioned from irregular hours to hours of equal length. Sometime between his active years of 147 to 127 BC, A Greek astronomer, geographer, and mathematician named Hipparchus developed the idea of fixed hours. Hipparchus was born around the region that is now known as Iznik, Turkey. However, when he was born it was known as Nicaea. He is often credited as the founder of trigonometry, and most famously, the first Greek to develop accurate models for the motion of the Sun and Moon. These fixed hours were determined during the equinox, when night and day periods were equal, thus creating 60-minute hours.
Mechanical Clocks and 12 Hour Systems
Italians were the first to introduce mechanical clocks. They originally counted 24 hours beginning the first half hour after sundown until the following day’s evening. This system considered the 24th hour to be the last daytime hour. Because the clocks produced 300 strokes per day, the mechanism wore out very quickly, becoming rather expensive and required a lot of rope. To save money and resources, some localities switched to ringing the series of 1 through 12 twice a day while distinguishing between the day and night. Through this, the 12-hour system was born, and time became a local matter. Localities used AM and PM, signifying the difference between the first and second 12 hours of the day.
Sir Sandford Fleming
Sir Sandford Fleming a Scottish Canadian engineer is also known as the father of standard time. Fleming was born in Scotland in 1827 and emigrated to Canada in 1845. He first worked as a surveyor and later an engineer for the Canadian Pacific Railway. Due to a misprint of his train schedule, Sir Sandford Fleming proposed a whole new time system for the world.
He proposed a world clock that originated at the center of the Earth and was not connected to any surface meridian. What he was proposing was the predecessor for Coordinated Universal Time or UTC. The abbreviation was chosen as a compromise between Coordinated Universal Time and temps universel coordoné. Fleming was an advocate for adopting the 24-hour clock in order to reform timekeeping, including time zones and establishing a universal prime meridian. At midsummer 1886, the Canadian Pacific Railway where he began his career, adopted the 24-hour clock, establishing Greenwich, England as the standard time, dividing the world into 24 time zones.
Coordinated Universal Time
The invention of the cesium atomic clock brought to light a new standard of timekeeping that was both more stable and more convenient than utilizing astronomical observations. This led to the introduction of Coordinated Universal Time on January 1, 1960. The US Naval Observatory, Royal Greenwich Observatory, and the UK National Physical Laboratory, all locations that broadcast UTC time, coordinated their radio broadcasts. Through this, method time steps and frequency changes were synchronized for accuracy.
As world wars evolved and passed, developed nations’ militaries began to adopt the 24-hour clock to heighten stability, unity, and improve the ability to strategize between geographically diverse units. Italy was the first to adopt the national 24-hour clock in 1893. The French Army adopted it in 1909, however, the rest of France did not change until 1912. The British Royal Navy utilized the system in 1915 during the First World War and the rest of the Allied forces embraced the systems thereafter. The United States Navy adopted the 24-hour system in 1920 and in 1942 near the start of the Second World War, the Army followed suit. Like the US Navy, Spain, Belgium, Portugal, and Switzerland also made the switch by 1920. By the early 1920s, most of Latin America had switched to the 24-hour system and in 1927 Germany converted as well. Eventually, both the US and Britain armed forces modified their 24-hour systems. Both used specialized time zones with alphabetical abbreviations. Below is a chart depicting the different time zones and their offsets. As you can see, every letter except “J” is used. Oftentimes, “J” is used to depict the observer’s local time.
Since its adoption, the military has simplified telling time even further by using hundreds as opposed to thousands. For example, 1000 is ten-hundred, and 0700 is oh-seven hundred, or zero-seven hundred. These modifications universalize the understanding of time throughout the military.
From Egyptian coffins in tombs almost lost by time to an Ancient Greek astronomer that standardized the hour, to a Scottish Canadian inspired by a missed train. The technology relies on it, all of humankind relies on it, it can be given, it can be taken away but once it’s used, time is gone. Military time, or the 24-hour system for time has a long history continues to be written as the world transforms and adapts to the ever-changing needs of civilization.