GMT

Greenwich Mean Time

A time zone that was used as a reference time for the world. It was based on the mean solar time at the Royal Observatory in Greenwich, London, England. GMT was widely used as a standard time reference in many industries and applications, including navigation, communication, and financial systems.

GMT was first implemented in the late 19th century and was used as the standard time reference for much of the 20th century. It was eventually replaced by Coordinated Universal Time (UTC) in the 1970s as a more accurate and uniform time standard for the world.

Despite its replacement by UTC, GMT is still used as a time zone by some countries, such as the United Kingdom. It is also commonly used in the aviation and shipping industries to refer to the time at the Prime Meridian, which is the line of longitude that runs from the North Pole to the South Pole and passes through the Royal Observatory in Greenwich, London.

• Abbreviation: GMT