The tropical cyclone forecasts/advisories are issued at times using a system based on Coordinated Universal Time (UTC). (In nonastronomical circles, it is sometimes called World Time, Z Time, or Zulu.) This system is used internationally so that forecasters throughout the world don't have to know the time zones of the data they are using. The table below shows how to convert from UTC time into military and civil time. In the example forecast/advisory, the valid forecast time is 1800Z. As indicated in the table below, 1800Z would be 2 p.m. EDT. For late-season storms that happen on standard time, the offset between Z time and EST would be +3 hours instead of +4 hrs.

Military Time Civil Time (Eastern Daylight) Z Time/UTC 0100 1 a.m. 0500Z 0200 2 a.m. 0600Z 0300 3 a.m. 0700Z 0400 4 a.m. 0800Z 0500 5 a.m. 0900Z 0600 6 a.m. 1000Z 0700 7 a.m. 1100Z 0800 8 a.m. 1200Z 0900 9 a.m. 1300Z 1000 10 a.m. 1400Z 1100 11 a.m. 1500Z 1200 12 Noon 1600Z 1300 1 p.m. 1700Z 1400 2 p.m. 1800Z 1500 3 p.m. 1900Z 1600 4 p.m. 2000Z 1700 5 p.m. 2100Z 1800 6 p.m. 2200Z 1900 7 p.m. 2300Z 2000 8 p.m. 0000Z 2100 9 p.m. 0100Z 2200 10 p.m. 0200Z 2300 11 p..m. 0300Z 0000 12 Midnight 0400Z