Meteorologists, as well as many other scientists, use the standard of Universal Coordinated Time (UTC) as a time reference to coordinate their measurements. Also known as Greenwich Mean Time (GMT), because Greenwich, England, is the place where the standard time is set, as well as Zulu—or “Z”—time, UTC employs the 24hour clock also used by the military. Thus, 0000 UTC indicates midnight and 1200 UTC is noon. A standard set by meteorologists is to make observations every six hours—at 0000, 0600, 1200, and 1800 UTC.