In 24 hours the Earth makes a complete revolution. Therefore, in different parts of the world, clocks show different times. For ease of reference, the entire territory of the Earth was divided into time zones. Their boundaries were to be determined by meridians and spaced 15 degrees from each other. But such a division is inconvenient for many states. Therefore, small countries calculate local time according to capital time. And in large countries it was necessary to allocate several time zones. But still, basic calculations, for example, the time of railway and flights, are carried out according to capital time. In Russia, such a reference point is Moscow. The time zone of other cities is calculated from it.
History of time zones
Until the 19th century, the issue of temporal confusion did not arise. Each state lived according to its own local time, and long distance travel was rare. But with the advent of railway communication, a problem arose in drawing up train schedules. Therefore, at the International Congress in the 80s of the 19th century, it was decided to divide the Earth’s territory into time zones. The countdown began from Greenwich to the east. The difference between them is one hour. Therefore, there were 24 belts in total. But until recently, all the issues related to this have not yet been resolved, and there is a lot of confusion in the countdown.
How time zones are divided
Theoretically, time zones follow meridians and are 15 degrees apart. But in practice they are often displaced, and it happens that they even disappear. This is due to the division of territory into states. And many countries, regardless of zones, introduce capital time. Therefore, the division into belts is now often arbitrary. But even in states that occupy a large territory, not only local time is important, but also capital time. For example, in Russia the countdown starts from the city, its belt is second from Greenwich. But all Russian cities count time not from him, but from Moscow.
Introduction to Russia
It was only in 1919 that the international time zone system was introduced in Russia. The country's territory was divided into 11 zones. But their border does not always follow the meridians. For example, Moscow is considered the starting point in Russia. Its time zone from Greenwich was adopted UTC+2. UTC is a worldwide designation for the world. But since the city is located on the border of zones, summer time was introduced, and the difference became UTC+3, which was more in line with natural rhythms.
What time zone is in Moscow now?
Several times throughout the history of the country there have been changes in the division into time zones. In the 30s it was canceled and the UTC+3 time zone remained in Moscow. It was believed that this was the most appropriate division, because in many countries, if a city lies on the border of the zones, it is classified as eastern. But from 1981 to 2011, summer time was reintroduced in Russia. Moscow began to be 4 hours ahead of Greenwich in the summer. And after the cancellation of the annual transfer of hands, the capital remained in the UTC+4 time zone. And now we live 2 hours ahead relative to the time adopted when dividing the country into time zones.
Time zones in Russia now
In 2010, the division into belts was changed in the country. And now Russia is located in 9 time zones. The Middle Volga and Chukotka-Kamchatka belts completely disappeared. Udmurtia and Samara switched to Moscow time, and Chukotka and Kamchatka switched to Magadan time. The difference between the zones is one hour. To calculate local time, you need to know what time zone you are in. How are time zones relative to Moscow calculated?
They are counted from Kaliningrad. This is the first time zone. The difference with Moscow time is 1 hour. After all, this city is located west of Moscow. All of European Russia lives according to the time of the capital. It differs from Greenwich by 4 hours. In our country this is the second time zone. It is the most populous. The next zone is the third, but the difference with Moscow is not 1, but 2 hours. It includes the Orenburg, Sverdlovsk, Tyumen and Chelyabinsk regions, the Khanty-Mansiysk Okrug, the Republic of Bashkortostan and some other administrative units.
The remaining time zones differ from each other by one hour. Their borders are not always related to the international division into time zones. For example, the fourth zone is adopted only in Altai and several neighboring regions, and the fifth - in Tyva, Khakassia and the Krasnoyarsk Territory.
Most often, the division into zones depends on the borders of republics and regions, but there are exceptions. For example, Yakutia lies in three zones, and the Sakhalin region - in two. The most distant regions of Russia differ in time from Moscow by 8 hours. The time in them is calculated from Moscow using the time zone formula - MSK+8. The plus sign means that the zone is located east, and the minus sign means that it is west of Moscow.
Due to constant and confusion with time zones, Moscow time does not coincide slightly with astronomical time. But still, it is counted in the country from the city of Moscow. You need to know the time zone so that when moving to another region, you can set the time on the clock correctly.
Instructions
Determine your time zone offset relative to the Greenwich meridian. You can find it out, for example, from the system time settings in your operating system. Click the clock in the notification area of the taskbar with the left mouse button, and an additional panel with a calendar and an analog clock will pop up on the screen. At the bottom of it there is a link “Change date and time settings” - click on it. The system will open an additional settings window with three tabs, one of which is “Date” and has a “Time Zone” section. In this section you will see the shift of your local time relative to the Greenwich meridian - the corresponding inscription could, for example, be like this: “UTC +04:00 Volgograd, Moscow, St. Petersburg.” This means that your operating system's system clock is shifted forward by four hours relative to time zone zero.
Subtract the time offset set for your time zone from the current time to determine the corresponding Greenwich Mean Time. For example, if your watch shows 26 minutes past nine in the morning, and the time zone corresponds to Moscow time, then this shift is equal to four hours, which means it is now 26 minutes past five in Greenwich time.
Use online services to determine Greenwich Time if you have Internet access. This is an even simpler way. For example, you can follow the link http://time100.ru/gmt.html and you will see the current Greenwich time immediately, without additional calculations.
Use the built-in functions of the programming language if you need to determine Greenwich Time programmatically - they are provided in most scripting languages. Most often, such functions refer to UTC time, and this is reflected in their names. For example, in the PHP language these are the gmdate and gmmktime functions, in the JavaScript language - a whole group of functions (getUTCDate, getUTCDay, getUTCMilliseconds and others), in the MQL5 language - TimeGMT, etc.
Sources:
- GMT
Due to the fact that the size of our planet is enormous, at the same period of time, different points of the Earth have their own local solar time. And in order to avoid confusion in clarifying the question: “So what time is it?”, the standard time system was adopted. And the Earth was conventionally divided into 24 time zones. The starting point was the zero meridian, from which time zones +1, +2, +3, etc. go to the east, and to the west: -1, -2, -3, etc. So, thanks to the time zone system, it is now quite easy to determine what you are looking for.
You will need
- - computer
- - time zone map
- - world map showing degrees of longitude
Instructions
Turn it on and click on the clock indicator in the lower right corner of the screen. Now, in the window that opens, click on the “Change date and time settings” function. And, in a new window, select the “Change time zone” function. You will see a long list of cities that belong to them. Of course, only capital cities are listed here and no small towns. So, if you want to find out the time zone of a small city, just find the capital of its country in this list, since, usually, there is one time zone within one country.
Use an ordinary world map, which shows in detail the middle meridians: 0°, 15°, 30°, 45°, 60°, etc. The fact is that one time zone occupies approximately 15°, but not clearly from 0° to 15°, from 15° to 30°, from 30° to 45°, etc., but with an offset that is equal to - 7 °30. And, in order to determine the boundaries of, for example, the UTC+1 time zone, you need to draw lines to the right and left of the middle meridian of 15° east longitude at a distance of 7°30". In order to determine the time zone of the place that is located, for example, in the area of 60° west longitude, you need to calculate its position in relation to the prime meridian: 15° - one, 30° - two, 45° - three, 60° - four. So 60° west longitude is the UTC-1 time zone .
Use a detailed map of time zones. Such a map is the simplest and most reliable way to determine the time zone of a particular point on the globe. Since here, not only the boundaries of each of the 24 time zones are indicated, but there is also a note indicating whether the country switches to summer time. For example, it looks like this: +1(+2), and means that the country belongs to the UTC+1 time zone, but in summer, it belongs to the UTC+2 time zone. Of course, do not forget to take into account that different hemispheres have summer and winter at different times. Another big advantage of such a map is the ability to determine whether there are different time zones on its territory, as in Russia, or, despite the large territory, only one zone is accepted, as in China.
note
Despite the generally accepted system of time zones, in reality, in order to maintain a uniform time within one country or administrative unit, the boundaries of zones are shifted, so in some places some time zones are superseded by neighboring ones.
Helpful advice
When determining your time zone, do not forget that in some countries local time differs from universal time not only by a standard hour, but also by an additional 30 or 45 minutes.
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 it is often denoted by the special abbreviation GMT. Where did it come from, and what does it mean?
GMT is the English phrase Greenwich Mean Time, which is like "Greenwich Mean Time". Mean time refers to the astronomical time of the meridian on which the Greenwich Observatory was previously located. This place is considered the “reference point” for all time zones. The Greenwich Royal Observatory became the point of reference for a reason. It appeared back in the 17th century in Greenwich (England). Calculations important for seafarers were carried out there, including those relating to time. When Great Britain became the largest empire, Greenwich time calculation spread to its dependent states, and at the end of the 19th century, almost the whole world adopted this reporting system. In 1884, even a special international conference was held to determine the “meridian of reference.” 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 time counting system was replaced by a more accurate one - by calculation according to Universal Coordinated Time, slightly different from the time on the Greenwich meridian. However, the abbreviation GMT is still often used as a tribute to tradition. What do the numbers in front of the GMT abbreviation mean? This is the time difference between 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 countdown should be carried out in the opposite direction: when it is 11 o’clock in London, then in the region with GMT-2 it is still 9. But we must not forget that not all countries have a clock change to winter time time. In 2011, it was also canceled in Russia. In this case, GMT will vary depending on the season.
The emergence of time zones on our planet was due to the banal convenience of communication and the division of different countries and cities in accordance with the real time of day. Scientists have divided the entire surface of the Earth into 24 time zones, taking into account a gap of 15 degrees of longitude. Time that is within the same time zone is considered the same.
Instructions
The decision to use time zones was made at the International Conference in 1884. The meridian passing through the Greenwich Observatory near London began to be considered the year's time reference point. It was this observatory that became the unifying link. It was originally built by order of King Charles II for sailors.
Definitions of the subject being described
The concept of GMT time (Greenwich Mean Time)
Time zones and GMT.
Definitions of the subject being described
GMT (Greenwich Mean Time)(English Greenwich Mean Time) is Greenwich Mean Time (Greenwich Mean Time), the time of the meridian passing through the former location of the Greenwich Royal Observatory near London (GMT operates in the UK, Ireland, Portugal).
GMT (Greenwich Mean Time) / GMT - this is world time - the value of Greenwich Mean Time (Greenwich Mean Time) (G M T) is equal to "Coordinated Universal Time" (U T C) to the nearest second - GMT = GMT). The name U T C, over time, will completely replace the term “GMT time”.
UTC (Universal Time Coordinated) is a time that is determined from astronomical observations of the daily movement of stars. It is unstable (within a second per year) and depends on the constant change in the speed of rotation of the Earth, the movement of geographic poles along its surface and the nutation of the planet’s rotation axis. Greenwich (astronomical) time is close in meaning to SGV (atomic time), and will still be used as its synonym. Another name - "ZULU time"
Abbreviations used
SGV (from English Universal Time Coordinated) - Universal coordinated time for the coordinated distribution of standard frequencies and precise time signals on television and the Internet - "World Time". Its synonym is "Universal Time Zone". The SGV time scale has been introduced since 1964 to harmonize the values of UT1 (astronomical measurements) and TAI (atomic clocks).
Universal Time UT (Universal Time) is the average solar time at the Greenwich meridian, determined from astronomical observations of the daily movements of stars. Its refined values are UT0, UT1, UT2. UT0 is the time at the instantaneous Greenwich meridian, determined by the instantaneous position of the Earth's poles. UT1 is the time at the Greenwich mean meridian, corrected for the movement of the earth's poles. UT2 - time, taking into account changes in the speed of rotation of the Earth.
UTC - Greenwich Mean Time (or Geographical) Time (English Greenwich Mean Time, GMT) - the time of the meridian passing through the old Greenwich Observatory, near London. Used to indicate time on weather maps. Synonyms for SGV are GMT (Greenwich Mean Time) and SGV.
Concept of timeGMT.
Previously, Greenwich Mean Time (Greenwich Mean Time) was considered the time reference point - time in other time zones was measured from Greenwich Mean Time. Now in this capacity it has been replaced by Coordinated Universal Time (CGT).
However, even now, when time is indicated and the time zone is important (for example, in Internet materials), time is usually specified in this format:
(it's the same time)
Those. it is Wednesday, December 22, 2004, 23:28:10 in the time zone two hours east of Greenwich (for example, in Kiev) - this means that in the Greenwich time zone (for example, in St. Helena) at that time it was 21: 28:10; in the GMT-7 time zone it was 14:28:10; and in Moscow (MSK, GMT+3) - already Thursday, December 23, 2004, 00:28:10.
Sometimes (in Russian-language meteorology) Greenwich is designated as UTC, deciphering it as “Greenwich Mean (or Geographic) Time.”
Time zones andGMT (Greenwich Mean Time).
GMT (Geographical Time) is
Standard time is a system of counting time based on dividing the Earth's surface into 24 time zones, every 15° in longitude. Time within the same time zone is considered the same. In 1884, at the International Conference it was decided to apply this system. The prime (zero) meridian, in accordance with the international agreement of 1883, is the Greenwich meridian with a geographic longitude of 0 ° 00 "00", dividing the globe into the western and eastern hemispheres. Passes through the former Greenwich Observatory (in the suburbs of London) Local Greenwich Time (GMT), agreed to be called universal or “World Time”.
In our country, we switched to standard time for the first time in 1919. At first it was used only in shipping, and since 1924 - everywhere.
There are 11 time zones on the territory of the Russian Federation. In fact, it is considered to be standard time plus 1 hour (during the whole year), for the reason that by Decree of the Council of People's Commissars in 1930, in the summer, the clock hands were moved 1 hour forward, to summer time. Back, it was decided not to transfer, and since then on the territory Russian Federation The so-called “maternity time” applies. Now, the difference with standard time is +1 hour in winter, and +2 hours in summer, with the addition of one more hour.
Moscow time zone (in winter): +3 (GMT (Greenwich Mean Time) + 3:00)
The boundaries of standard time (see figure) are drawn taking into account physical and geographical features - along large rivers, watersheds, as well as along interstate and administrative boundaries. States can change these boundaries within the country.
The international system U T C (World Time is used; it is designated GW/GMT or, which is the same thing, GW), as well as - difference local and Moscow time - MSK. The plus sign means east, the minus sign means west of the starting point.
The transition to summer time (one hour forward) and winter time (one hour back) occurs on the last Sunday of March and October, respectively.
Sources
WikiPedia - the free encyclopedia
kakras.ru - collections, folklore, reference books.
Yandex. Dictionaries.
internationaltimezones.co.uk
Investor Encyclopedia. 2013 .
See what "GMT" is in other dictionaries:
GMT- noun Greenwich Mean Time; the time as measured at Greenwich in London, used as an international standard for measuring time: The accident happened at 9.33 a.m. GMT on 14 May. * * * GMT UK US /ˌdʒiːemˈtiː/ noun [U] MEASURES … … Financial and business terms
GMT- steht für: Greenwich Mean Time Gewerkschaft Metall Textil, Teilgewerkschaft des Österreichischen Gewerkschaftsbundes Giant Magellan Telescope, astronomisches Teleskop Generic Mapping Tools, Open Source Software zur Erstellung von Karten… … Deutsch Wikipedia
