So 1600Z (or 4 pm in the Prime Meridian time zone) is actually 10 am in Wisconsin during the winter. For example, Wisconsin is six hours behind the Prime Meridian time zone in the winter, because it is six time zones west of the Prime Meridian zone. is earlier than the local time at the Prime Meridian - that is, the sun rises in England hours before it does in the U.S.

and the earth rotates toward the east, local time in the U.S. Throughout each time zone, time remains the same and differs by an integral number of hours from the time in the Prime Meridian zone based on the number of time zones west of the Prime Meridian zone. 360 divided by 24 is 15, which is why we add one hour for every time zone, or 15 degrees longitude away from Greenwich, England, to convert to local time. Each meridian is the center of each standard time zone.Ī convenient way to explain this concept to students is that there are 360 degrees in a full rotation which on earth is equal to 24 hours. The system consisted of 24 standard meridians of longitude 15 degrees apart from each other, beginning with the Prime Meridian through Greenwich, England. in 1884 and agreed on a system for worldwide standard time. Following Fleming’s initiative, delegates from 27 nations met in Washington, D.C. Sir Sanford Fleming, a Canadian railway planner and engineer, developed the first plan for a worldwide standard time reference system in the late 1870’s in response to scheduling challenges created by railway routes that spanned multiple communities in the United States and Canada. In order for scientists to communicate about data, it is necessary to have a global standard for referencing time.Ī standard time was originally adopted to end the confusion caused by each community’s use of its own local time. These stand for Coordinated Universal Time and Zulu time respectively, a way to tell time worldwide. You have probably noticed that most satellite images will have times expressed in UTC or Z time.

Wisconsin utc time zone