When trying to find out what time it is in another region and in another country, you will most likely come across the concept of "time zone". But often it is denoted by the special abbreviation GMT. Where did it come from, and what does it mean?
GMT is an abbreviation of the English phrase Greenwich Mean Time, which translates to Greenwich Mean Time. Mean time is understood as the astronomical time of the meridian, on which the building of the Greenwich Observatory was previously located. This place is considered the "reference point" for all time zones. The Royal Greenwich Observatory has become a reference point for a reason. It appeared in the 17th century in the city of Greenwich (England). There were made important calculations for seafarers, including those concerning time. When Great Britain became the largest empire, the calculation of time "according to Greenwich" spread to dependent states, and at the end of the 19th century this reporting system was adopted by almost the whole world. In 1884, even a special international conference was held on the definition of the "reference meridian". Time in other countries was determined by the distance from the Greenwich meridian, that is, from the time zone where Great Britain was located. In the seventies, the world time system was replaced by a more accurate one - to calculate the universal time, which is slightly different from the time on the Greenwich meridian. Nevertheless, the abbreviation GMT is still often used as a tribute to tradition. What do the numbers before the abbreviation GMT mean? This is the time difference between the Greenwich Observatory and another selected area. For example, if you are in the GMT + 3 time zone, for example, in Moscow, then the time difference with the reference meridian is three hours, while in Moscow the time is later. The minus sign in front of the number means that the time should be counted in the opposite direction: when it is 11 o'clock in London, then in the region with GMT-2 there is still 9 o'clock, but we should not forget that not all countries have a clock change to winter time. In 2011, it was canceled in Russia as well. In this case, GMT will change depending on the season.
