What is the difference between UTC and GMT time?
Universal Time Coordinates (UTC) is equivalent to Greenwich Mean Time (GMT). This is also equivalent to Zulu (Z) Time and is measured on the Prime Meridian (O degrees longitude) in Greenwich, England. By international agreement, the term UTC is recommended for all general timekeeping applications, and use of the term GMT is discouraged. For more information on how this applies in Australia see the section on ‘Timestamping’ on our ‘About Satellite Pictures’ page at: http://www.bom.gov.au/info/about_satpix.