Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London which is measured at midnight. Enter the Meridian Courtyard to get your essential photo standing on the Meridian Line and explore some of the oldest parts of the site including the Astronomer Royal's house. A time zone is a region if the planet that observes a uniform standard of time for commercial, social and legal purposes. Time zones to the east of the Greenwich meridian are later and time zones to the west of the Greenwich meridian are earlier. Greenwich mean time or Greenwich meridian time (GMT), the former name for mean solar time at the site of the Royal Observatory in Greenwich, England, which is located on the prime meridian prime meridian, meridian that is designated zero degree (0°) longitude, from … The Royal Greenwich Observatory started the process for a unified standard time by becoming the Prime Meridian or the zero longitude for the world. Inextricably linked with Greenwich Mean Time, it also sits at the centre of our system of time zones. There is an imaginary line running through the UK called the Prime Meridian. zone numbers east of th'eprime meridian, are negative numbers (-1, 2 etc.)

The IANA time zone identifiers for Greenwich Mean Time are GMT, Africa/Abidjan, Africa/Accra, Africa/Bamako, Africa/Banjul, Africa/Bissau, Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome, Africa/Monrovia, Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, America/Danmarkshavn, Atlantic/Reykjavik and Atlantic/St_Helena. The prime meridian is the imaginary line that divides Earth into two equal parts: the Eastern Hemisphere and the Western Hemisphere. For purposes .of navigation, the. The Greenwich meridian time zone is 7 1/2 degrees east and 7 1/2 degrees west of zero degrees longitude. Greenwich Mean Time or GMT is the clock time at the Royal Observatory in Greenwich, London. Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London, reckoned from midnight.At different times in the past, it has been calculated in different ways, including being calculated from noon; as a consequence, it cannot be used to specify a precise time … GMT stands for Greenwich Meridian Time – that’s something we learnt in school – but what does it have to do with a watch? The historic Royal Observatory is the home of Greenwich Mean Time. At this point, although France still declined to adopt the Greenwich Meridian; the … To see more detail view our larger format world time zone map.