The fundamental means of measuring time is the rotation of the earth. The original standard by which all clocks are regulated is furnished from observation of the stars and their relationship to the earth. Add military time to one of your lists below, or create a new one. 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. 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 one p.m. Where this gets confusing is when you have to translate to the current time in your location. The East Coast of the United States is five hours later than Greenwich Mean Time. So, 1300Z at GMT is the same as 0800 on the East Coast. When you first hear someone in the military give you the time, you may have to pause a few seconds and do the quick math in order to determine the time of day. Commercial pilots also use the 24-hour clock to avoid misunderstandings. Let’s look at those three elements of military time in more detail. The U.S. Army didn't officially adopt military time until 1942. With email marketing, it's a must to understand and follow the legislation and other requirements of the country or countries where your email recipients are located. Email regulations vary among regions and countries, and significant fines are imposed for breaching these laws. As you know, holidays and special celebrations differ from one country to another.