New Delhi. Greenwich Mean Time (GMT), a unit used to measure time around the world. In simple words, it can also be called the average time, during which the Earth rotates 360 degrees on its axis in the 24-hour period. Its history is quite old, ‘Greenwich’ is a village in England on the basis of which its foundation was laid. It can be said about it that it is located in the center of the earth. However, there are many technical facts related to it, all are important but the question is how many can be understood.
GMT (Greenwich Mean Time) is the annual average over which the Sun passes through the Royal Observatory Greenwich, England. It was recognized on this day in 1884 and by 1972 it had become the standard of ‘International Civil Time’. Actually this process started from the 16th century when the pendulum was invented. Only after this the relationship between time and solar system time period was discovered. During the 19th century, every city in England had its own time, there was no national standard, resulting in many problems.
Between 1850 and 1860, railways and trade expanded and economic activities increased. In such circumstances, there was a need for a national standard time, then the Railways itself decided a standard time. Finally, in December 1847, British Railways accepted GMT, which was also called ‘Railway Time’. After 1850, public clocks in small and big cities in England were set on the basis of GMT and by 1880 it was fully accepted.
In the year 1884, GMT’s Greenwich Meridian was established as ‘Prime Meridian’ for two reasons.
Secondly, in the 90s, about 70 to 75 percent of the world’s trade and transactions depended on sea charts. It had already accepted Greenwich as the ‘Prime Meridian’.
Apart from this, there was another reason on the basis of which importance was given to Greenwich because its longitude was at 0 degree. It was argued that this would benefit a large population of the world. The Shepherd Gate Clock was the first clock in the world to publicly display GMT. Also known as the ‘Slave Clock’, it is linked to the Shepherd Master Clock at the Royal Observatory. On the other hand, ‘Royal Observatory’ is also called the home of GMT.
There is one more thing without which the GMT topic is incomplete, the International Date Time. Days are decided on the basis of this and time is decided on the basis of GMT. Every country in the world has its own time zone which is decided on the basis of how or under what condition the longitude line passes through it. For example, in India this line passes at 82.5 degrees, due to which India is 5.30 hours ahead of GMT.
Some other things related to GMT are very important, without which it is difficult to understand its functioning. The most notable among these are latitude and longitude. Latitude lines are parallel, their distance is equal, they run from east to west and their total number is 181. Whereas the longitude lines run from north to west, the distance between its lines is not equal and they are also far away from the equator. During the British rule, there used to be two time zones in our country, the first based on Kolkata and the second based on Mumbai. After his departure, IST (Indian Standard Time) was created, that is, a country will have only one standard time. Our GMT is +5:30 i.e. about 5:30 hours ahead of Greenwich Mean Time.