The U.S. military operates on the 24-hour clock. The day starts at midnight which is written as 0000. The last minute of the day is written as 2359, or one minute before the next midnight.

When it comes to operational matters (such as communications, training exercises, deployments, ship movements, aircraft flights, etc.), the military often coordinates with bases and personnel located in multiple time zones. To avoid confusion, the

military uses Greenwich Mean Time (GMT) based on the mean solar time at the Royal Observatory in Greenwich, England. The U.S. military refers to GMT as Zulu Time, and they attach the suffix “Z” (Zulu) to ensure the time zone referred to is clear. (For example, 0315Z.)

In Oklahoma, Central Standard Time (CST) is 6 hours behind GMT, so 8:30 am CST = 1430Z. During the summer, Central Daylight Time (CDT) is 5 hours behind GMT. For more information on GMT see https://greenwichmeantime.com/.