Still in the Windows computer settingsThe time zone is specified by the GMT abbreviation. What is it and how does it relate to the modern time management system UTC? We will tell about it in our article. To determine the time at the point of location relative to Greenwich can not everyone. But we will try to clarify this issue in a popular language. First of all, you need to answer the question: "GMT - what is this?" How is this abbreviation?
British snobbery
In the old days, the time was set at noon.When the sun was at its zenith, that is, it reached its highest point in the visible sky, it was believed that it was twelve o'clock in the afternoon. With the development of international trade, it became necessary to harmonize time into a single system. The zero meridian became the point of such a reference. It passes through the Royal Observatory in the town of Greenwich, near London.
Thus, the abbreviation GMT is decryptedlike Greenwich Mean Time. All the territories that are located west of Greenwich are behind its time, and those that are located east of it are ahead of it. There is another significant meridian on the surface of the planet Earth. This is the line of change of dates. The territory located to the east of it lives (in the literal sense of the word) yesterday afternoon. In 1972, the new abbreviation UTC changed GMT. What is this time? The abbreviation stands for "Universal Coordinated Time."
Time Zones
In Russian metrology is usedabbreviation SGB instead of GMT. What is this? Letters are deciphered as "Average geographical time." But again, we cannot get away from Greenwich. After all, the whole world is counting hours from the zero meridian. If to be punctual and accurately determine the time for each point on the globe, you need to know its distance from Greenwich to the west or east. A Coordinated Universal Time (in other words, UTC) displays mostly noon in certain countries (or parts of them). If GMT is a time that knows no political boundaries, then time zones often extend to the whole state (if it doesn’t extend very far from west to east). Thus, UTC + 0 is not in the Greenwich Observatory and on the zero meridian, but in the whole of Great Britain and Ireland, as well as Iceland, Portugal, Morocco, etc. in GMT.
Summer and winter time
In high-latitude countriesthe length of daylight varies greatly with the time of year. Therefore, the northern countries often switch to summer time. Residents of these states shift the hands of the clock forward by one hour. This happens on the last Sunday of March. The UK is also on the list of countries practicing the summer time period. But the true noon from April to October is then observed at one o'clock in the afternoon, because the Greenwich Mean Time does not depend on the season.
Countries lying near the equator, wherethe length of daylight at any time of the year is approximately twelve hours, do not shift the seasonally arrows. They constantly live in the winter (true) time. On this basis, the Russian Federation decided not to move the hands by an hour forward every year. By the way, another country lying in high latitudes, refused to switch to summer time. This is Iceland. The island nation lives in Greenwich Mean Time (GMT + 0). The UK and Ireland lying approximately on the same meridian are in UTC + 0 in the winter and in UTC + 1 in the summer.
What are UTC and GMT for?
Time is a concept of loving accuracy.For coordinated actions to dispatch services located at remote points of the Earth, it is necessary to know how many hours, minutes and seconds are there. Also, broadcasters of various frequencies have a need for coordinated time. UTC is necessary to establish a specific standard for navigation and scientific purposes. Throughout the nineteenth century, the sailors of the British fleet, plying the oceans, calculated the time in GMT. Moving to the west of Greenwich, they took the clock, and to the east - they added. According to this principle, the globe is now divided into time zones. For example, Vladivostok time corresponds to GMT + 11, Georgian - GMT + 4, Hawaiian-Aleutian - GMT-10, Moscow - GMT + 4, Eastern Standard Time (it is used for New York and the territories of the USA and Canada adjacent to the Atlantic Ocean). also in Jamaica, Panama, Haiti, Bahamas) - GMT-5.
