The 24-Hour Military Time System

The 24-Hour Military Time SystemThe 24-Hour Military Time SystemWhen you first hearsomeone in the military give you the time, you may have to pause a few seconds, do the quick math in buchen to determine the time of day. Unless you grew up in the military household, you are likely not familiar with the way the military tells time. Civilians typically break up the day into AM and PM which are 2 to 12-hour blocks of the day denoting morning and afternoon/evening. The 24-Hour Clock However, the military operates off a 24-hour clock, beginning at midnight (which is 0000 hours). So, 1 AM is zero one hundred (0100) hours, 2 AM is zero two hundred (0200) hours, and so on up until 11 PM which is 2300 hours. After noon (1200 hours) to translate the regular time in the afternoon and evening, you simply add 12 hours to be within military standards. For instance, 1 PM is 1300 hours and 5 PM is 1700 hours. Heres the whole list Midnight (1200 AM) - 0000 hrs100 AM - 0100 hrs200 AM - 0200 hrs 300 AM - 0300 hrs400 AM - 0400 hrs500 AM - 0500 hrs600 AM - 0600 hrs700 AM - 0700 hrs800 AM - 0800 hrs900 AM - 0900 hrs1000 AM - 1000 hrs1100 AM - 1100 hrs1200 PM - 1200 hrs100 PM - 1300 hrs200 PM - 1400 hrs300 PM - 1500 hrs400 PM - 1600 hrs500 PM - 1700 hrs600 PM - 1800 hrs700 PM - 1900 hrs800 PM - 2000 hrs900 PM - 2100 hrs1000 PM - 2200 hrs1100 PM - 2300 hrs For most daily things, military personnel uses local time as a reference. In order words, report to duty at zero seven hundred (0700), would mean you have to be at work at 7 AM, local time. The Commander wants to see you at fifteen hundred (1500) hrs, means you need to be in the Commanders office at 3 PM, local time. When using local time, the Military observes Daylight Savings Time, if recognized by the state or country that the base is located in. Designating Time Zones When it comes to operational matters (such as communications, training exercises, deployments, ship movements aircraft flights, etc.), the mi litary must often coordinate with bases and personnel located in other time zones. To avoid confusion, in these matters, the military uses the time in Greenwich, England, which is commonly called Greenwich Mean Time (GMT). However, the U.S. Military refers to this time zone as Zulu Time, and they attach the Zulu (Z) suffix, to ensure the time-zone referred to is clear. For easy reference in communications, a letter of the alphabet has been assigned to each time zone. The timezone for Greenwich, England has been assigned the letter Z. TheMilitary phonetic alphabetfor the letter Z is Zulu. The East Coast of the United States is denoted with the R letter (Romeo). For example, a military message or communication might state, The ship will cross into the area of operations(AOO) at 1300Z. That means the ship would arrive in the AOO when it is 1 PM in Greenwich, England. Where this gets confusing is when you have to translate to the current time in your location. The East Coast of the Unit ed States is five hours later than Greenwich Mean Time. So, 1300Z at GMT is the same as 0800 on the East Coast. To make it even more confusing, the number changes when the United States observes Daylight Savings Time (DST). So, instead of 5 hours later than Greenwich Mean Time, the East Coast of the United States during the months of March (2nd Sunday) and November (1st Sunday) the time difference will be six hours. The East Coast of the United States will be denoted with the Q letter (Quebec) during Daylight Savings Time. Time Zone Confusion Why does the military call this time Zulu time? You would think that the world could be divided equally into 24 one-hour equals a day. However, due to the International Date Line (middle of Pacific Ocean), there are actually three more zones created and many of the zones are not exactly an hour apart (as the Sun travels). Some are only 30 to 45 minutes apart. But, somehow the system works as it is used mainly by ocean-going commerce vessels and the worlds Navies.