The 24 Hour Time Clock
Military time or astronomical time is based on a 24 hour clock. It is a method of keeping time in which the day runs from midnight to midnight divided into 24 hours. It is the most commonly used time notation in the world. Using this military time or 24 hour time the day starts at midnight which would be 00:00 with the last minute of the day 23:59 one minute before the next midnight. Sometimes 24:00 may refer to the end of a given date at midnight. Often time tables may show 16:00 - 24:00 which would be an equivalent to 4:00 pm to 12:00 midnight. Another example would be if using 12 hour time if the time was currently 10:15 am in the morning the corresponding military time would be simply 10:15. However, if the time was 2:30 pm on a 12 hour time clock the corresponding military time would be 14:30.
To the left you can see a chart showing a 12 hour time clock next to a 24 hour or military time clock.
Military time is commonly used by the military, government, public transportation, hospitals, meteorology, astronomy, emergency services and often with computers just to name a few. When speaking in military time 09:00 may be stated as "zero nine hundred" or "oh nine hundred". When written in military time by the military they will often write 0752 leaving out the colon rather than 07:52 as civilian time. Greenwich Mean Time is Coordinated Univeral Time zone and is designated with a Z at the end of the military time shown as 0752Z. Local time is designated with a J shown as 0752J and the eastern time zone is designated with a R shown as 0752R. Each military time zone has a corresponding letter and name.
Wikipedia 24 Hour Clock October 7, 2012