What is the significance of gmt

The second hour hand points to a second time scale that reads to 24 instead of 12, typically located on the innermost portion of the watch dial. This red pointer on the GMT watch face has also been a confusing element for the uninitiated. This has been put in place to show the time relevant for the outer hour dial for the secondary location that you have chosen. It tells you the time based on a hour clock.

The former is indicated by the conventional hour, minute and seconds hands. Local time can be adjusted quickly by jumps of the hour hand without affecting either the hour hand or the minute hand. What is the significance of GMT? It officially became 'Railway Time'. There were two main reasons for this. The first was that the USA had already chosen Greenwich as the basis for its own national time zone system. As the reference for GMT, the Prime Meridian at Greenwich therefore became the centre of world time and the basis for the global system of time zones.

Therefore this also became the start of the Universal Day. The meridian line is marked by the cross-hairs in the Airy Transit Circle eyepiece. Find out more about the Airy Transit Circle.

The Shepherd gate clock can be seen at the gates to the Royal Observatory. It was the first clock ever to show Greenwich Mean Time directly to the public. It is a 'slave' clock, connected to the Shepherd master clock which was installed at the Royal Observatory in From that time until , the Shepherd master clock was the heart of Britain's time system. Its time was sent by telegraph wires to London, Edinburgh, Glasgow, Dublin, Belfast and many other cities.

By , time signals were also sent from the clock to Harvard University in Cambridge, Massachusetts via the new transatlantic submarine cable. In terms of the distribution of accurate time into everyday life, it is one of the most important clocks ever made. The first thing you notice about the clock is that it has 24 hours on its face rather than the usual That means at 12 noon the hour hand is pointing straight down rather than straight up.

The clock originally indicated astronomical time, in which the counting of the 24 hours of each day starts at noon. The clock was changed in the 20th century to indicate Greenwich Mean Time, in which the counting of the 24 hours of each day starts at midnight. Learn the story of Greenwich Mean Time in our publications. Keep track of time with our famous Shepherd Gate clock replica for your wall. Visit us. Royal Observatory.

Plan your visit. Top things to do. Discover gifts from the home of time Learn the story of Greenwich Mean Time in our publications. An autumnal photograph of the Prime Meridian of the World. As the reference for GMT Greenwich Mean Time , the Prime Meridian at Greenwich became the centre of world time and the basis for the global system of time zones in Buy Now.

A stylish hour analogue clock that will make a statement on any wall, with its bold monochrome face, and matte black metal casing How old is Earth? How fast can you think? How long is a light year and how short is a femtosecond?