Modern electronic systems like navigation depend heavily on precise time and time interval (PTTI) and work from what we now call the USNO Master clock. Now after completing Step 1 you find the number to be less than 12, we are in the morning. On Military Time, morning starts at 0000 and ends at 1200. This is essentially the same format as the 12 hour clock except you will see leading zeros before the hour digit. Generally, when conversing with other military personnel in the same time zone, you will use the local time zone rather than GMT. The military also has names and letters for time zones around the world. The world is split into 25 time zones that include all letters of the alphabet except the letter J. Military time is important primarily due to the ease of communication it provides. Unlike standard AM/PM time, military time does not create confusion as frequently as timekeeping that requires an AM or PM notation. Have you ever set an alarm for 7 PM instead of 7 AM? If you wish to write out military time, you should remove the colon and the seconds as mentioned above. You can always use the handy Military Time Converter for quick calculations for other military times. Once you get used to working in military time, using the 12 hour clock feels wrong. There is definitely an adjustment period, but once you master it, you will never look back. The difference between 4 am and 4 pm in military time is twelve hours. You can visualize this difference by seeing how 4 am and 4 pm are written using military time below. To convert to military time, you have two options. The first option for converting from civilian to military time is to use a military time chart, such as the one in the image below. In the United States, NASA uses military time down to thousandths of a second. While the U.S. military and militaries around the world use military time, so do other large operators whose business takes them through different time zones.