What does Greenwich mean? What is UTC or Greenwich Mean Time? GMT is the definition

Ceramics, fireclay 06.02.2024

Ceramics, fireclay

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. In accordance with the international agreement of 1883, the prime ("zero") meridian is considered to be the one that passes through the Greenwich Observatory in the suburbs of London. Local Greenwich Time (GMT), agreed to be called Universal Time or "World Time"

On the territory of Russia, since March 28, 2010, there are 9 time zones (before that there were 11 time zones). The Samara region and Udmurtia switched to Moscow time (second time zone). Kemerovo region. (Kuzbass) - to Omsk (MCK+3). Kamchatka Territory and Chukotka - to Magadanskoye (MSK+8). In these five subjects of the Federation, on March 28, 2010, the clock hands were not moved.

Two belts are being abolished - the third (Samara, MSK+1) and the eleventh (Kamchatka, MSK+9). There are 9 of them in total, and the maximum time range in our country is reduced from 10 to 9 hours.

In Russia, since March 2011, after the transition to summer time, the clock hands are no longer moved throughout the year.

In 2012, the advantages of permanent winter time over summer are being discussed again, at all levels, and therefore a transition (this fall) to permanent, year-round winter time is possible.

Stable time is better for health. In the autumn-spring off-season, the body does not have to particularly adjust its biorhythms. Technical services and transport workers no longer have to, as before, when changing the hands of the clock, reconfigure equipment and change schedules.

Time zone of Moscow, according to stable time: +4 (GMT + 4:00)

The boundaries of zone time 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 UTC/GMT or, which is the same thing, UTC), as well as the difference between 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 in spring and autumn, respectively. This rule applies in the European Union, Egypt, Turkey, New Zealand... The dates and procedure for transfer may vary slightly in terms of timing. Most countries have abandoned the autumn-spring change of clock hands: Russia and Belarus (since 2011), Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, India, China, Japan, Singapore, Taiwan...

World time - UTC/GMT - the value of Greenwich Mean Time (G M T) is equal to "Universal Coordinated Time" (U T C) with an accuracy of one second - GMT=UTC). The name U T C, over time, will completely replace the term “Greenich time”

Rice. 2 Map - World time zones and their offsets from UTC/GMT (Greenwich Time)

Table - time zones of cities around the world (UTC/GMT), in the summer

Kamchatka	UTC/GMT+12
Magadan, Sakhalin.	UTC/GMT+12
Vladivostok	UTC/GMT+11
Yakutsk	UTC/GMT+10
Irkutsk	UTC/GMT+9
Krasnoyarsk	UTC/GMT+8
Omsk	UTC/GMT+7
Ekaterinburg	UTC/GMT+6
Moscow Moscow time, Sochi city	UTC/GMT+4
Minsk "Eastern European Time" (EET)	UTC/GMT+3
Paris "Central European Summer Time" (CEST - Central Europe Summer Time Zone)	UTC/GMT+2
London Greenwich Time / Western European Time (WET)	UTC/GMT+1
"Mid Atlantic Time"	UTC/GMT-1
Argentina, Buenos Aires	UTC/GMT-2
Canada "Atlantic Time"	UTC/GMT-3
USA - New York "Eastern Time" (EDT - US Eastern Daylight Time Zone)	UTC/GMT-4
Chicago (Chicago) "Central Time" (CDT - US Central Daylight Time)	UTC/GMT-5
Denver (MDT - US Mountain Daylight Time)	UTC/GMT-6
USA, Los Angeles, San Francisco "Pacific Daylight Time" (PDT - Pacific Daylight Time)	UTC/GMT-7

An example of winter and summer time designation: EST / EDT (Eastern Standard / Daylight Time Zone).
If, somewhere, winter time is considered standard, then it can be abbreviated, for example: ET, CT, MT, PT

Table - time zones of cities and regions in Russia, since 2011.
Local time difference shown:
MSK+3 - with Moscow;
UTC+7 - with Coordinated Universal Time (UTC = GMT)

Name winter / summer		Bias relatively Moscow time	Offset relative to UTC (World Time)
USZ1	Kaliningrad time - the first time zone	MSK-1	UTC+3:00
MSK/MSD MSST/MSDT	Moscow time	MSK	UTC+4:00
SAMT/SAMST	Samara	MSK	UTC+H:00
YEKT/YEKST	Yekaterinburg time	MSK+2	UTC+6:00
OMST / OMSST	Omsk time	MSK+3	UTC+7:00
NOVT/NOVST	Novosibirsk, Novokuznetsk Kemerovo, Tomsk. Barnaul	MSK+3	UTC+7:00
KRAT/KRAST	Krasnoyarsk time Krasnoyarsk, Norilsk	MSK+4	UTC+8:00
IRKT/IRKST	Irkutsk time	MSK+5	UTC+9:00
YAKT/YAKST	Yakut time	MSK+6	UTC+10:00
VLAT/VLAST	Vladivostok time	MSK+7	UTC+11:00
MAGT / MAGST	Magadan time Magadan	MSK+8	UTC+12:00
PETT/PETST	Petropavlovsk-Kamchatsky	MSK+8	UTC+I2:00

Note: MSK = MSD (Moscow Summer Time) all year round

Terms and Definitions

Switching to Daylight Saving (Summer) Time (DST - Daylight Saving (Summer) Time) - moving the clock hand forward one hour, which was done annually on the last Sunday of March in order to get an additional hour during daylight hours, to save electricity (for lighting, etc. ). The return to winter time was carried out recently. Sunday in October. These transitions affected the biorhythms of the human body, his well-being, and it took a week of adaptation to get used to it. Manipulation of clock hands is a common reason why workers and employees are late for work.

The prime (prime) meridian 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)

GMT (Greenwich Mean Time) - "Greenwich Time"- on the Greenwich meridian. Determined from astronomical observations of the daily motion 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 UTC (atomic time), and will still be used as its synonym. Another name is "Zulu Time"

In Russian-language meteorology, GMT is designated as SGV (Greenwich Mean / or Geographical / Time)

GMT= UTC (accurate to 1 second)

Time zone (Standard Time Zone) - difference with World Time UTC/GMT (example: UTC/GMT+4 - fourth time zone, east of Greenwich)

H:mm:ss - 24-hour format (example: 14:25:05). Minutes and seconds - with leading zeros

h:mm:ss - 12-hour format (example: 02:25:05 PM - "two and a half hours in the afternoon" - 14:25:05). Minutes and seconds - with leading zeros

AM - designation of time before noon in a 12-hour format (short version - "A")
PM - designation of time after noon in a 12-hour format

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 - time at the instantaneous Greenwich meridian, determined from the instantaneous position of the Earth's poles

UT1 - 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

TAI - time according to atomic clocks (International Atomic Time, since 1972). Stable, reference, never translated. Time and frequency standard

Time in the GPS navigation system has been in effect since January 1980. No amendments are introduced to it. It is ahead of UTC time by one and a half dozen seconds.

UTC (from English Universal Time Coordinated)- Coordinated Universal Time for the coordinated distribution of standard frequencies and time signals over radio, television and the Internet - "World Time". Its synonym: "Universal time zone"

The UTC time scale has been introduced since 1964 to harmonize the values of UT1 (astronomical measurements) and TAI (atomic clocks).

Unlike Greenwich Mean Time, UTC is set using atomic clocks.

The speed of rotation of the earth is slowing down, and therefore, corrections are introduced into the UTC scale regularly, after a year or two or three, on June 30 or December 31 (leap seconds - “Coordination Second”), so that U T C is no more than a second ( more precisely, 0.9 s) differed from astronomical time (determined by the movement of the Sun), as UT1 lagged behind by a second. This international rule was adopted in 1972.

Time ratio in 2009: UTC (universal) lags behind TAI (atomic) - by 35s. Time in the GPS navigation system is 15 seconds ahead of UTC (counting since 1980, the difference is increasing) T glonass = Tutc + 3 hours (corrected, so the discrepancy between them does not exceed 1 ms.)

Precise time signals (for clock synchronization) are transmitted via radio channels, television, and the Internet - in the UTC system. More precisely, you can place it, for example, on the Mayak radio signal, but only on the long-wave or medium-wave range (on the “ground-surface wave”). On VHF/FM radio, the signal may be delayed up to several seconds from the true one.

In watches with automatic synchronization (English Radio controlled), time correction occurs from base stations, on ultra-long waves. This system was developed in Europe.

Exact local time service numbers in Russian cities 100 - Moscow Voronezh Cheboksary Chelyabinsk 060 - Bryansk Kaliningrad Krasnodar Murmansk St. Petersburg Samara Mobile operators do not have such a service, since a mobile phone is not limited geographically and can work not only in a specific city, but also in roaming .

UTC time is not converted neither in winter nor in summer, therefore, for those places where there is a conversion to summer time, the offset relative to UTC changes (in Moscow, before the abolition of winter time in 2011, the difference was: in winter - UTC+3, in summer - UTC+4).

Standard abbreviations for the names of calendar months and days of the week in English (used in RSS and others): January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Monday Tuesday Wednesday Thursday Friday Saturday Sunday Mon Tue Wed Thu Fri Sat Sun

GMT - 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 GMT are GMT and UTC.

______________________________________________

Literature

“Time and calendar” - M.: Nauka. 1989

Global (satellite) navigation systems GLONASS (Russia), GPS (USA), Galileo (European Union) - make it possible to determine, using navigator devices, including portable ones, the current location (coordinates), trajectory and speed of movement of objects in any point on our planet and in near-Earth space.

Depending on the method of operation and purpose, satellite GPS (Global Positioning System) navigators can be used for automobiles (car navigators), portable, marine, etc. The most common imported ones are Garmin, Mio, etc. There are completely autonomous configuration options - with batteries charging from solar panels or miniature thermoelectric generators (thermocouples). The navigation system is built into modern communicators, smartphones and cell phones, allowing you to receive not only the geographic coordinates of the receiver’s location, but also the system time with an accuracy of a fraction of a microsecond.

Russian GLONASS has been operating since the mid-90s. The orbital constellation includes more than two dozen operating satellites. The system operates throughout Russia. Since 2009, transport, including passenger transport, has been massively equipped with this system.

Navigators are produced in Russia (Glospace SGK-70 and others) that can work simultaneously with several navigation systems - GLONASS, GPS, Galileo.

Glospace supports the SMILINK system (shows traffic jams) and can create detour routes. Signals can be received from several satellite systems at once.

G P S maps - electronic maps for navigators and other mobile devices (communicators, PDAs / PDAs, smartphones, etc.) with GPS function.

A time calculator is needed to find out what time it will be in the place you need.

For example, you want to call your beloved grandfather in Vladivostok to congratulate him on his birthday. You know that the guests will sit down to the festive table at half past seven in the evening, and you want to congratulate him at that very moment.

But by coincidence, you yourself are in the city of Darwin, Australia, and you need to find out what time, Australian time, the birthday celebration will begin.

This is where our calculator comes in handy. To find out the time, you just need to indicate half past six and the date of your birthday in the left column, select Vladivostok there and click on the "=" button between the columns

How to use the time calculator?

On the calculator panel you can see two columns - source And result

Source- this is the date, time and place known to you. Result- the required date and time.

You can set the time and date in the source by simply clicking on the corresponding field.

After setting the date and time, you need to specify the location for which you have set the time. In the birthday example, this would be the city of Vladivostok.

Below the fields for setting the date and time there is an item time is set to- this is a switch. With it, you can indicate whether you specified the time for a specific city or for a time zone. To find out the time of Vladivostok from our example, you can select both the city itself and the time zone of Vladivostok - VLAT.

To switch from indicating a city to indicating a time zone, simply left-click on the switch.

Name is the name of the object for which the time was set. Based on the value of the switch, this could be the name of the city or the name of the time zone.

After setting the date, time and source location, you need to specify which location you are looking for the time for. In our happy birthday example, it's Darwin, Australia. Using a similar switch, you can also specify both the city itself and its time zone - ACST

Once you have set all the values, just click on the " = " between fields, and find out the time you are looking for!

All the buttons of our calculator are labeled, and if you have forgotten the meaning of a particular button, hover your mouse over it. After a second, a hint will appear with its meaning.

time, which in Russian meteorological terminology sounds like Greenwich Mean Time or geographic time, which got its name due to the meridian passing through the Royal Observatory located in Greenwich

Determination of GMT time, the history of its appearance and brief information about the Royal Observatory in Greenwich and the prime meridian, general characteristics, meaning and methods for determining Greenwich time, GMT time zones with an explanation of why they have such a name, familiarization with the international standard time format ISO 8601 and time scale

Expand contents

Collapse content

GMT is the definition

GMT is Greenwich mean solar time, which in English sounds like Greenwich Mean Time, is also called the astronomical time of the prime meridian passing through the Greenwich Royal Observatory in London, until 1972 Greenwich time was considered a single reference point for time zones, now such a reference point is universal time coordinated or UTC (Universal Time Coordinated).

GMT time on time zone map

GMT is astronomical (or mean solar) time of the meridian passing through the Royal Greenwich Observatory in London (which is zero although it is located at 51° 28′ 40″ north latitude and 0° 0′ 5.31″ east longitude ). Now such a reference point is coordinated universal time (in English Universal Time Coordinated, or UTC). Often (in Russian meteorological terminology) Greenwich Mean Time is translated as SGV, which means “Greenwich Mean (or geographic) time.”

GMT is an abbreviation of the English phrase Greenwich Mean Time, which translates as “Greenwich Mean Time”.

GMT is Greenwich Mean Time, the time of the meridian passing through the former location of the Royal Greenwich Observatory near London (GMT valid in Great Britain, Ireland, Portugal).

GMT is the mean solar time of the meridian passing through the former site of the Royal Observatory Greenwich near London.

GMT is Greenwich Mean Time (GMT) is in the same time zone as Coordinated Universal Time (UTC).

GMT, what is it? Greenwich Mean Time was outdated and Coordinated Universal Time (UTC) was introduced instead.

GMT is 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 UTC (atomic time), and will still be used as its synonym.

GMT what is it Greenwich Mean Time (GMT) is equal to Coordinated Universal Time (UTC) to the nearest second - GMT=UTC. The name UTC, over time, will completely replace the term “Greenwich time”.

GMT is the time of the meridian passing through the former site of the Royal Observatory Greenwich near London. Previously, GMT was considered the reference point for time - time in other time zones was measured from Greenwich. Nowadays Coordinated Universal Time (UTC) is used in this capacity.

GMT, what is it - is it a time that is used to indicate time on weather maps. Synonyms for GMT are GMT and UTC.

GMT, this is where it is the time used as the reference point for time in other time zones before the introduction of Coordinated Universal Time (UTC).

The history of the appearance of geographic time GMT

In 1675, Charles II ordered "the exact location of objects in latitude and longitude for the needs of navigation and astronomy." The task was mainly intended for the scientist John Flamsteed, the building for his work was built in Greenwich by the famous Christopher Wren. Flamsteed House is the main building of the Royal Observatory and the first building to be built in the UK for scientific research.

The Astronomer Royal did something simple - he recorded the position of the prime meridian where he worked. And over the next two centuries, most navigators in the world compiled their maps based on the Greenwich meridian.

However, until the end of the 18th century, no one knew exactly how to measure longitude - the distance to the east or west of a given meridian. People knew how to calculate latitude (the distance south or north of the equator) from the position of the North Star, but no such system existed for longitude.

In 1754, the British government offered a reward of 20,000 pounds to anyone who could find a solution. The award was ultimately given to watchmaker John Harrison, who in 1772 designed a clock that could accurately measure time on board a ship and allow the navigator to determine the ship's east or west position to within 30 miles (48 km).

"Greenwich Time" was adopted as a standard in 1884. According to the international treaty, it was established that “each new day begins precisely at midnight when the celestial meridian passes through the sighting axes of the telescope of the Royal Observatory at Greenwich.”

The conference was held in Washington in 1884 - in a vote in which 25 countries took part, it was decided that Greenwich Mean Time was the standard for measuring time around the world. The voting results were 22 for, 1 against and 2 abstained. The Dominican Republic is the only country to vote against it. Representatives of France and Brazil were not sure of the correctness of the decision and decided to abstain. France adopted Paris as the prime meridian and used it in its time measurement system until 1911, and in its navigation system until 1914. Representatives from Brazil believed that a neutral prime meridian that did not intersect either the United States or Great Britain would be preferable. Poor Brazilians returned home to the disapproving cries of other representatives: “Someone definitely had to show off.”

At the same time, the International Meridian Conference in Washington decided that Greenwich was assigned a zero degree of longitude. The decision was based on the fact that this choice would inconvenience the least number of people.

To help others set their clocks exactly to Greenwich Mean Time, in 1833 Astronomer Royal John Pond installed a “time ball” over the observatory. This ball still continues to descend sharply every day at exactly 13:00 (GMT in winter, British Summer Time in summer).

Before 1954, Greenwich Mean Time (GMT) was based on time measurements taken at the Greenwich Observatory. Later, GMT began to be calculated using astronomical observation data from other observatories that remained operational. Now GMT is often called "Universal Time" (English: Universal Time, UT). Nowadays, Universal Time is calculated from observations of extragalactic radio sources, and then converted into several forms, including UT0 (UT at a remote observatory), UT1 (UT corrected for the movement of the poles (English) Russian) and Coordinated Universal Time (UTC).

In 1894, the observatory survived an explosion attempt. This may have been the first case of "international terrorism" in Britain. The bomb was detonated by a 26-year-old French anarchist named Martial Bourdin. It is unknown whether he deliberately chose the Greenwich Observatory to carry out the terrorist attack, or whether the bomb detonated there by accident. This incident prompted Joseph Conrad to write The Secret Agent.

However, even before the convening of the Washington Conference, some countries switched to the new system. Below we will look at how the standard time system gradually penetrated into various countries, and at first it was mainly used only on railways and telegraphs, but soon received legal rights and began to be used everywhere.

The first four countries to adopt GMT (1848-1883)

The first, even before the convening of the Washington Conference in 1884, were four countries to switch to the new Greenwich time system - Great Britain, Sweden, the USA and Canada:

Great Britain - 1848;

Sweden - 1879;

Canada and USA - 1883.

Transition to Greenwich Time in different parts of the world (1994-1905)

By 1905, among the leading countries of the world that did not accept the new system were France, Portugal, Holland, Greece, Turkey, Russia, Ireland, as well as most of the countries of Central and South America, excluding Chile.

Thirty-six states have already introduced standard time, and in twenty of them the Greenwich meridian served as the basis for counting time; of the remaining sixteen, only two countries did not agree to switch to this system. France, together with Algeria, did not at first recognize this system and used Paris mean time as the state time (by law of March 14, 1891). In all other countries - since time on the railways there was already counted everywhere in the new system - a transition to standard time was made. In December 1891, Pasquier wrote in Ciel et Terre that “the almost unanimous agreement of civilized states regarding the Greenwich meridian should encourage the adherents of other meridians to lay down their arms; and from now on all efforts should be directed towards the implementation of watchmaking unification, simple, rational and practical.”

France's transition to GMT time (1996-1911)

On October 27, 1896, Deputy Deville introduced a bill in the Chamber of Deputies proposing to establish Greenwich Mean Time (GMT - Greenwich Mean Time) in France. This bill, with some amendment - maternity time should be expressed in Parisian mean time, reduced by 9 minutes 21 s (which generally corresponded to Greenwich mean time, which, however, was not mentioned) - passed through the Senate on February 24, 1898, after whereupon he was sent to a parliamentary commission, where he stayed for twelve long years. Apparently, the Ministries of Commerce, Industry, Posts and Telegraphs and Public Works were ready to accept this bill, but it aroused vigorous objections from the Ministry of Public Education and the Navy.

Finally, on March 9, 1911 (radio had already become a reality), a law was passed in France, according to which, starting from the night of March 10-11, “maternity time in France and Algeria should be considered Parisian mean time with a delay of 9 minutes 21 seconds.” . This law was in effect until August 9, 1978, when a decree was passed requiring French daylight saving time to be determined on the basis of Coordinated Universal Time (UTC - Coordinated Universal Time, which by definition cannot differ from GMT time by more than 0.9 s) by adding to or subtracting from it the exact number of hours

Countries that were the last to adopt the GMT system (1912-1972)

As for other countries, Portugal switched to a time system based on the Greenwich meridian in 1912; Brazil and Colombia - in 1914; Greece, Ireland, Poland and Türkiye - in 1916; RSFSR in 1919; Argentina and Uruguay - in 1920.

Holland, on whose railways Greenwich time was established as early as 1892, until 1909 used Amsterdam mean time instead of local time for all other purposes; it was forced to switch to Central European time on May 19, 1940 during the German occupation; its application was finally approved in 1956. The last state to adopt the new system was Liberia, where until January 1972, maternity time was 44 minutes 30 seconds behind Greenwich Mean Time.

Royal Observatory Greenwich and the Greenwich Meridian

The Royal Observatory, Greenwich is Britain's oldest scientific institution. Greenwich is an eastern district of London (formerly a suburb). Thanks to the work of the observatory, the word "Greenwich" became a household word throughout the world, associated with clocks and the prime meridian.

Now the Royal Observatory is a whole complex of small museums. First of all, this is an astronomical gallery with interactive instruments designed to make the sky understandable to humanity. In 1990, astronomers and telescopes moved to Cambridge, and at the end of 1998, by special decree of the Queen, the observatory was closed altogether.

British astronomers have long used the Royal Observatory as a basis for measurements: four different meridians were drawn through the building. The prime meridian - the origin of longitude - was established in 1851 and adopted at an international conference in 1884. It passed through the meridian circle of George Airy installed at the observatory. For a long time, the prime meridian was marked by a brass ribbon stretched across the observatory's courtyard. Then the brass was replaced with stainless steel, and since December 16, 1993, in the night sky of London, the prime meridian is marked by a green beam of a bright laser from the observatory, directed due north.

Currently, the buildings of the Greenwich Observatory house a museum of astronomical and navigational instruments, which is part of the National Maritime Museum. Among them is the famous marine chronometer "H4" by John Harrison, along with three predecessors (these chronometers now belong to the British Ministry of Defense ).

There you can also see several more exhibits representing the history of the development of means of measuring precise time, necessary in astronomy and maritime navigation. An astronomical clock invented in the mid-20th century is also presented. Soviet scientist F. M. Fedchenko - the most accurate among mass-produced pendulum clocks. And outside, on the wall at the gate of the observatory, there is another famous clock - the Shepherd gate clock. This is one of the first electric driven clocks.

Another unique exhibit in this museum is the 28-inch Howard Grubb refractor telescope, created in 1893 and remains the largest refractor in the UK.

In February 2005, work began on a £15 million renovation of the observatory, including the creation of a new planetarium, exhibition galleries and classrooms. On May 25, 2007, the 120-seat Peter Harrison Planetarium was officially opened.

In May 2013, a monument to Yuri Gagarin was unveiled on the territory of the observatory.

The main "tourist attraction" of Greenwich is, of course, the Greenwich meridian, which can be seen here! It runs in a strip across the paved courtyard and under the wall. This is the prime meridian, which separates the Eastern and Western Hemispheres, from which time zones are measured.

General characteristics of Greenwich time

Greenwich Time (GMT) or, as it is also called, Universal Time (UT) is associated with the movement of the Sun, which is recorded by an observer at the Greenwich meridian with a longitude of 0°. This time is used in the UK as local standard time during the winter months. In the summer months, British Summer Time is introduced, which is obtained by increasing GMT by one hour, thereby achieving a more convenient coincidence of the working day with daylight hours. Many other countries have also adopted a similar system for changing clocks.

The time we use in everyday life is called mean solar time. It is based on the average length of a sunny day. The true length of the solar day varies throughout the year; this is due to the uneven movement of the Earth around the Sun and the fact that the length of the solar day is determined by the change in the right ascension of the Sun, measured along the equator, and the Sun moves along the ecliptic.

The correction that must be added to mean solar time to obtain true solar time is called the equation of time. The mean solar time at a given point is called local time; it varies with longitude.

To avoid difficulties with the use of local time, the entire globe was divided into 24 time zones, and within each time zone a single standard time was established, corresponding to the position of the central meridian of that zone.

Universal Time (UT)

In astronomical reference books and calendars, as well as when making observations, they use Universal Time (UT) or, as it is also called, Greenwich Mean Time - mean solar time of the prime meridian, which is taken to be the meridian passing through the Greenwich Observatory in England.

It varies from 0 hours to 24 hours and is counted from midnight. Since universal time is the same for all points on Earth, its use eliminates any confusion in time. Every real observatory (and every self-respecting observer) has a clock that shows universal time.

There are tables that allow you to change from regular local time to universal time. Sidereal or sidereal time is another system of time measurement based on the length of the sidereal day of time between two successive passages of a star through the same meridian point.

The sidereal day is approximately 3 minutes 56 seconds shorter than the average solar day. The sidereal day, beginning at the moment of the upper culmination of the vernal equinox, like the solar day, is divided into 24 sidereal hours. Local sidereal time is determined by the right ascension of the celestial meridian (the hour angle of the vernal equinox.

To determine local sidereal time, you can use a clock that “hurries” by about 4 minutes every day. Unlike electric watches, ordinary mechanical watches can be easily adjusted for these purposes. Most yearbooks indicate Greenwich sidereal time, i.e. time is midnight Greenwich Mean Time (0h UT).

The difference between local and universal time is equal to the longitude of the given observation location, expressed in hourly units; longitude also determines with sufficient accuracy the difference between sidereal time and sidereal time according to Greenwich Mean Time. The time zones into which the Earth's surface is divided can be used to calculate Universal Time (UT) from local (winter) time.

Greenwich Mean Time

Greenwich Mean Time is astronomical (the time of the meridian passing through the Royal Greenwich Observatory in London (which is zero although it is located at 51° 28′ 40″ north latitude and 0° 0′ 5.31″ east longitude). Now such a point The reference point is coordinated universal time (in English Universal Time Coordinated, or UTC).Often (in Russian meteorological terminology) Greenwich Mean Time is translated as SGV, which means “Greenwich Mean (or geographical) time.”

In 1964, the uniformly variable universal time scale (UTC) was adopted as standard by the International Telecommunication Union. The UTC scale is based on the uniform atomic time scale (in French, Temps Atomique International or TAI), which makes it more convenient for use in everyday life.

UTC was adopted as a standard in 1972 to replace the obsolete Greenwich Mean Time (GMT) scale. The need for a new time scale arose when it was discovered that the GMT scale was uneven because it depended on fluctuations in the Earth's daily rotation. And since the Earth rotates unevenly, the Greenwich Meridian also rotates unevenly. The uneven rotation of our planet is expressed in the movement of the axis of rotation in the body of the Earth itself, as a result of which the North and South Poles shift along the surface, which means that the planes of the true meridians also change their position.

Previously, GMT was considered the reference point for world time, that is, time in other time zones was counted from the Greenwich (zero) time zone. Now the world's time zones are expressed simply as a positive or negative offset from UTC. Do not forget that UTC time is not converted either in summer or winter. Therefore, where there is a transition to daylight saving time, when moving the hands, the offset relative to UTC simply changes.

Greenwich meridian (prime meridian) is geographic meridian passing through the axis of the passage instrument of the Greenwich Observatory. The Greenwich meridian serves as the origin of geographic longitude; is the middle meridian of the zero time zone. Local mean solar time at the Greenwich meridian is widely used in astronomy (to synchronize universal time).

Greenwich Mean Time

The modern time zone system is based on (Universal Time), on which the time of all time zones depends.

Local time in many countries of the Northern Hemisphere (but not all) increases by 1 hour in the summer (in the Southern Hemisphere it simultaneously decreases by 1 hour), and in the winter it returns to normal, standard time, which often also changes. Due to these seasonal and non-seasonal changes in local time in broadcasting, international transport, radio communications, e-mail and other international means of communication, there is enormous confusion regarding time connections between different countries.

Theoretically, the 24 time zones of the globe should be limited to meridians passing 7 ° 30 "east and west of the middle meridian of each zone, and universal time operates around the Greenwich meridian. However, in reality, to maintain a single time, within the same administrative or natural unit , the boundaries of the zones are shifted relative to the meridians; in some places, some time zones even “disappear”, getting lost between neighboring ones.

At the North and South Poles, the meridians converge at one point, and therefore the concept of time zones, and at the same time local time, loses its meaning there. It is believed that time at the poles corresponds to universal time, although at the Amundsen-Scott station (South Pole) New Zealand time is in effect, and not universal time. World time – UTC/GMT – the value of Greenwich Mean Time (GMT) is equal to Coordinated Universal Time (UTC) accurate to the second - GMT=UTC. The name UTC, over time, will completely replace the term “Greenwich time”.

GMT (Greenwich Mean Time) - "Greenwich time" - on the Greenwich meridian. Determined from astronomical observations of the daily motion 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 UTC (atomic time), and will still be used as its synonym. Another name is "Zulu Time"

Since 1900, the average solar day has increased by 0.002 atomic seconds, and therefore Greenwich Mean Time diverges from International Atomic Time by approximately 1 second for every 500 days.

Taking into account this progressive phase shift between the two time scales, and without giving up the high accuracy offered by atomic clocks, a compromise was found in 1972 that led to the definition of the concept of Coordinated Universal Time (UTC), which is now used as the official measure of time in the world . Essentially, UTC time flows as international atomic time, and when the difference with Greenwich Time reaches 1 second, 1 second is added to the UTC scale, which is called a leap second.

Thus, the difference is always kept less than 0.9 seconds. The addition of a jumping second is reported by the International Earth Rotation Service (IERS), which continuously monitors the rotation speed. The best dates to add a jumping second are June 30 and December 31. By the way, the term UTC is also a compromise between the English CUT (Coordinated Universal Time) and the French TUC (Temps Universel Coordlnaire).

Precise time signals are transmitted via radio, television, and the Internet - in the UTC system. In Russian-language meteorology, GMT is designated as GMT (Greenwich Mean or Geographical Time).

Transition to summer and winter time GMT

Additional ambiguity is introduced by the use of “summer time” in many countries.

When you switch to daylight saving time, your time shifts relative to the universal time. In addition, not everywhere the transition to daylight saving time and back occurs simultaneously. For example, when it is summer in the countries of the Southern Hemisphere, it is winter in the Northern Hemisphere, and vice versa.

The so-called summer time was the brainchild of William Willett, a London builder. In a brochure sent in 1907 to many members of parliament, city municipalities, businessmen and various organizations, he noted: “For almost six months, the Sun illuminates the Earth every day in the hours when we are still sleeping, and quickly approaches the horizon, having passed its way to the west, when we return home after a hard day...” Willett proposed, “to improve well-being and cheerfulness,” on each of the four Sundays in April, gradually move the clock hands forward by 20 minutes and return them back in the same way in September.

But, in addition to improving health and vitality, this will lead, as Willett argued, to a reduction in energy consumption: at a cost of 0.1 pence per hour, this will save 2.5 million pounds. Art. Although the scheme proposed by Willett looked ridiculous and met with considerable resistance, especially from farmers, nevertheless, in 1909 a bill was drawn up to introduce summer time, which was repeatedly considered in Parliament, but was never passed before the war.

Daylight saving time, pros and cons

In April 1916, summer time was introduced (to save energy) in Great Britain, and a week later - in almost all countries, both allied and enemy. Willett died a year earlier, without seeing his ideas put into practice. Many states abandoned daylight saving time immediately after the end of the war, others repeatedly introduced and abandoned it, and some countries maintained this time shift throughout the year. During the Second World War, England lived on “summer time” in the winter, and in the summer introduced “double summer time” (DBST, two hours ahead of GMT)

The transition to summer time (one hour forward) and winter time (one hour back) occurs on the last Sunday of March and October, respectively. This rule is valid in Russia (until March 2011), the European Union, the USA, etc. The dates and procedure for changing the clock hands in other countries may differ slightly in terms of timing.

Daylight saving time, reduction of time zones

78 countries use some form of daylight saving time (of which 10 countries do not use it in all regions), and 161 countries do not use it. In the northern hemisphere, daylight saving time is used almost everywhere in the USA, Canada, Mexico (except for a number of states and provinces), completely in all European countries except Iceland, Russia and Belarus, as well as in Morocco, Turkey, Iran, Azerbaijan, Syria, Jordan, Lebanon, Israel, Palestine. In the southern hemisphere, summer time is used in Australia (in a number of states), New Zealand, Paraguay, Uruguay, Brazil (in a number of states), Chile, Namibia.

Japan, China, India, Singapore, as well as the republics of the former USSR: Uzbekistan, Tajikistan, Turkmenistan, Georgia, Kazakhstan, Kyrgyzstan, refused to introduce summer time. At the same time, Georgia, Turkmenistan, Kyrgyzstan and most of Kazakhstan and Uzbekistan retained “maternity time”. Russia has refused to change hands since the fall of 2011, having adopted the law “On the Calculation of Time.” Russia was soon followed by Belarus.

However, not all of America observes daylight saving time.

Daylight saving time is not observed in Hawaii, the American Samoa Islands, Guam, Puerto Rico, the Virgin Islands, and Arizona (except for the Navaja Indian Reservation, which observes it). The Navaja Indian Reservation, due to its large size and location in three states, observes daylight saving time.

In the period 1968-1971. England has tried to experiment by keeping Daylight Saving Time (called British Standard Time - BST) all year to align its time with that of other countries in the European Economic Community. This innovation caused general discontent in the country, especially among the population of the westernmost regions of Great Britain. The experiment had to be stopped, and since 1972, Britain lives according to GMT in winter and BST in summer. Most other countries are now doing what France is doing - maintaining daylight saving time throughout the year.

UTC (Universal Coordinated Time) - universal coordinated time, sometimes called "Zulu time", the basis of civil time, based on atomic time. UTC is a legacy of Greenwich Mean Time (GMT), and is sometimes also erroneously referred to as GMT. Please note that UTC time is not converted in winter and summer. Therefore, for those places where there is a change to daylight saving time, the offset relative to UTC changes.

Daylight saving time in Russia

Until 1930, in our country every year during the summer the clock hands were moved forward an hour, and in the fall they were again set in accordance with standard time. By government decree of June 16, 1930, summer time was established throughout the country, which, in contrast to standard time, was called maternity time. On April 1, 1981, for economic reasons, the principle of moving time forward an hour in summer was restored. Thus, in the summer, our country lived on double summer time.

Cancellation of the transition to winter time in Russia

In 2015, there will be no transition to daylight saving time in the Russian Federation. In October 2014, Russia set its clocks back an hour and adopted permanent winter time. More precisely, this time is not called winter, but zone time. Note that other countries switched their clocks to daylight saving time already in March 2014 (on the night of the 30th).

Summer time - features of the transition

Disagreements between legal and geographical criteria for GMT time

Since legal, political, socio-economic criteria in addition to physical or geographic criteria are used in drawing time zones, actual time zones do not exactly adhere to meridian lines.

The Greenwich time zone was, drawn in purely geographical terms, to consist of the area between the meridians 7°30"W and 7°30"E. As a result, there are European locales that, despite being located in an area with "physical" UTC time, use a different time zone (UTC+1 in particular); on the other hand, there are European areas that use UTC, even though their "physical" time zone is UTC−1 (eg most of Portugal), or UTC−2 (westernmost part of Iceland). Because the UTC time zone in Europe is "shifted" to the west, Lowestoft in Suffolk, East Anglia, England at only 1°45"E is the easternmost setting in Europe in which UTC is applied.

Countries (or parts of it) west of 22°30"W ("physical" UTC−2) then use UTC

The westernmost part of Iceland, including the northwestern peninsula and its main city Isafjer Ur, which is west of 22°30"W, uses UTC. Bjargtangar, Iceland is the westernmost point at which UTC is applied.

Most of Portugal, including Lisbon, Porto, Braga, Aveiro and Coimbra. (Only the easternmost part, including towns such as Bragança and Guarda, lies east of 7°30"W.) Since the Treaty of Windsor in 1386 (the oldest diplomatic alliance in the world), Portugal has maintained a close relationship with Britain, which may explains its choice of UTC. Madeira, further west, also uses UTC. A more likely explanation is that during the mid-1970s, when Portugal was on Central European Time all year, it did not start to become easy in Lisbon in the winter until 08:30.

Western part of Ireland, including the cities of Cork, Limerick and Galway. Westernmost tip of Northern Ireland, including the main county town of County Fermanagh, Enniskillen. Extreme western part of the Outer Hebrides, west of Scotland; for example, Vatersay, an inhabited island and the westerliest settlement in Great Britain, is at 7°54"W. If uninhabited islands or rocks are taken into account St Kilda, west of the Outer Hebrides, at 8°58"W, and Rockall, at 13°41"W, must be turned on.

Spain (except the Canary Islands, which use UTC). Parts of Galicia lie west of 7°30"W (physical UTC−1), while there is no Spanish territory east of 7°30"E (physical UTC+1). Spain's time is a direct result of Franco's Presidential Order (issued in the Boletín Oficial del Estado of 8 March 1940) abandonment of Greenwich Mean Time and the clock advancing one hour, effective 11:00 pm on 16 March 1940. This is an excellent example of the political criteria used in the figure time zones: the time change was passed "subject to convenience with national time, keeping pace with that of other European countries."

How to determine Greenwich time?

The time zone in which the Greenwich Royal Observatory was once located near the British capital was taken as the zero reference point for time zones. Greenwich Mean Time is abbreviated as GMT (Greenwich Mean Time). Now there is a refined standard, which is designated as UTC (Coordinated Universal Time). It differs from Greenwich Time by less than one second and is used more often in precise calculations, and when determining the time of day in different parts of the planet, Greenwich Time is still relevant.

You can find out GMT time, for example, from the system time settings in your computer's 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 called “Date and Time” 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 advanced four hours from 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.

In the JavaScript language there is a whole group of functions (getUTCDate, getUTCDay, getUTCMilliseconds and others), in the MQL5 language - TimeGMT, etc.

Why is the time zone called GMT?

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?

How can I find out the time zone of my region?

GMT is an abbreviation of the English phrase Greenwich Mean Time, which translates as “Greenwich Mean Time”. Mean time refers to 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.

Greenwich Mean Time

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 - calculated according to Coordinated Universal 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 abbreviation GMT 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.

Moscow time = GMT 3

The minus sign in front of the number means that the time must be counted 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 this case, GMT will vary depending on the season.

Several countries define their local time in relation to Greenwich Mean Time. Some examples:

United Kingdom - Interpretation Act 1978, section 9 provides that whenever an expression of time occurs in the law, the time referred to shall (unless otherwise specifically stated) be taken to be Greenwich Mean Time. In subsection 23(3), the same rule applies to deeds and other instruments;

Belgium - Decrees 1946 and 1947 set legal time as one hour ahead Greenwich Mean Time;

Republic of Ireland - Standard Time (Amendment) Act, 1971, section 1, and Interpretation Act 2005, section 18(i);

Canada: Interpretation Act, R.S.C. 1985, p. I-21, section 35(1).

Time zones of cities and countries around the world according to Greenwich Mean Time (UTC/GMT)

Time zone or Time zone is part of the earth's surface (land and sea) on which the same time applies. Geographically, the earth is divided into 24 equal zones, where the time on adjacent zones differs by 1 hour. However, actual time zones are different from geographic boundaries because they are determined by boundaries between states, government or administrative territories.

A time zone described in connection with the global time coordinator (GMT). The main time zone reference point is the Prime Meridian (0° longitude), passing through the Greenwich Observatory in London. As a result, instead of the generally accepted designation UTC is still used in GMT (Greenwich Mean Time).

The international UTC system is used (World Time; it is designated UTC/GMT or, which is the same thing, UTC), as well as the difference between local and Moscow time - MSK. The plus sign means east, the minus sign means west of the starting point.

For greater convenience (in order not to enter local time for each degree of longitude), the Earth's surface was conventionally divided into 24 time zones. The boundaries of time zones are determined not by meridians, but by administrative units (states, cities, regions). This is also done for greater convenience. When moving from one time zone to another, the minutes and seconds (time) are usually preserved; only in some countries, local time differs from world time by 30 or 45 minutes. The Greenwich Observatory in the suburbs of London was taken as the reference point (prime meridian or belt).

At the North and South Poles, the meridians converge at one point, so time zones are usually not observed there. Time at the poles is usually equated to universal time, although at polar stations it is sometimes kept in its own way.

The formation of time zones is associated with the desire, on the one hand, to take into account the rotation of the Earth around its axis, and on the other hand, to define territories with approximately the same local time so that the time differences between time zones are multiples of one hour. As a result, it was decided that there should be 24 time zones and each of them should cover an area approximately 15° in width (± 7.5° relative to the corresponding mean meridian). The starting point was the Greenwich meridian, the prime meridian, and the middle meridian of the zero time zone.

The modern time zone system is based on Coordinated Universal Time (Universal Time), on which the time of all time zones depends. In order not to enter local time for each degree (or each minute) of longitude, the Earth's surface is conventionally divided into 24 time zones. When moving from one time zone to another, the values of minutes and seconds (time) are preserved, only the value of the hours changes. There are some countries in which local time differs from world time not only by a whole number of hours, but also by an additional 30 or 45 minutes. However, such time zones are not standard time zones.

Theoretically, the 24 time zones of the globe should be limited by meridians passing 7 ° 30 "east and west of the middle meridian of each zone, and universal time operates around the Greenwich meridian. However, in reality, to maintain a uniform time within the same administrative or natural unit, zone boundaries are shifted relative to the meridians; in some places, some time zones even “disappear”, getting lost between neighboring ones.

Time zones of the world and their numbers

At the North and South Poles, the meridians converge at one point, and therefore the concept of time zones, and at the same time local time, loses its meaning there. It is believed that time at the poles corresponds to universal time, although at the Amundsen-Scott station (South Pole) New Zealand time is in effect, and not universal time. The territories of nine countries of the world are located in several time zones:

Russia has 11 time zones;

Canada 6 time zones;

The USA also has 6 time zones (including Hawaii, excluding island territories: American Samoa, Midway, Virgin Islands, etc.);

There are 4 time zones in the autonomous territory of Denmark - Greenland;

Australia and Mexico each have 3 time zones;

Brazil, Kazakhstan, Mongolia and the Democratic Republic of Congo each have 2 time zones.

The territories of each of the remaining countries in the world are located in only one time zone.

Despite the fact that China is located in five theoretical time zones, a single Chinese Standard Time operates throughout its entire territory.

The only administrative-territorial unit in the world whose territory is divided into more than two time zones is the Republic of Sakha (Yakutia), which is a subject of the Russian Federation (3 time zones). In the USA and Canada, the boundaries of time zones are very winding: there are often cases when they go through a state, province or territory, since territorial affiliation with a particular zone is determined at the levels of second-order administrative-territorial units.

Samoa time zone

Samoa's time zone: UTC/GMT-11-SST is Samoa Standard Time.

Time zone in Hawaii

Hawaii has its own time zone, Hawaiian Standard Time. There is no daylight saving time, which means that in Hawaii, time is two hours behind US West Coast time in the summer, and three hours behind US West Coast time in the winter. in Hawaii and the Aleutian Islands, the Hawaiian-Aleutian time zone (UTC-10, symbol HAST).

Alaska time zone

Alaska Time Zone: 9 hours behind Greenwich Mean Time (GMT - 09:00), i.e. GMT -9

US Pacific Time

Pacific Standard Time is 1:00 PM or minus 8 hours from Greenwich Mean Time - GMT - 8. This zone includes the following states such as (California; Nevada; Oregon; Washington State);

Mountain Time USA

Mountain Standard Time is 2:00 PM or minus 7 hours from Greenwich Mean Time - GMT - 7. This zone includes states such as (Arizona; Colorado); Idaho, Montana, Nebraska (part of the state), New Mexico (New Mexico), Oregon (part of the state), South Dakota (western part), Texas (part of the state), Utah (Utah), Wyoming (Wyoming) ));

US Central Time

Central Standard Time is 3:00 PM or minus 6 hours from Greenwich Mean Time - GMT - 6 This zone includes states such as Alabama, Arkansas, Florida, Illinois, Indiana ( part of the state), Iowa, Kansas, Kentucky (western part of the state), Louisiana, Michigan (part of the state), Minnesota (Minnesota), Mississippi (Mississippi), Missouri ( Missouri), Nebraska, North Dakota, Oklahoma, South Dakota (eastern part of the state), Tennessee (western part of the state), Texas (main part of the state ), Wisconsin (Wisconsin));

US Eastern Time

Eastern Standard Time - 4:00 PM or minus 5 hours from Greenwich Mean Time - GMT - 5. This zone includes states such as Connecticut, District of Columbia, Delaware, Florida (main part of the state), Georgia (Georgia), Indiana (main part of the state), Kentucky (Kentucky) (eastern part of the state) Maine (Maine), Maryland (Maryland), Massachusetts (Massachusetts), Michigan Michigan (main part of the state), New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island ( Rhode Island), South Carolina, Tennessee (eastern part of the state), Vermont, Virginia, West Virginia);

South American Pacific Time

In South America, this time zone is called EST - South American Pacific Time (Eastern Standard Time), which is - GMT - 5 for Bogota, Lima, Quito;

Atlantic Standard Time

Atlantic Standard Time, summer - North American Eastern Time and all year round - Eastern Caribbean Time - GMT - 4;

South American Eastern Time

Most of Brazil is in the same time zone (South American Eastern Time) as the country's capital, Brasilia. In winter, time in Brasília, the entire Federal District, all states of the Southeast, Southern and Northeastern regions, as well as in the states of Goiás, Tocantins, Pará and Amapá, corresponds to the GMT -3 time zone;

Time zone in Greenland

The territory of Greenland is divided into four time zones. The capital and most major cities on the southern coast lie in the GMT/UTC -3 time zone, and the time here is 6 hours behind Moscow.

Mid-Atlantic time

Middle Atlantic time, - UTC/GMT-2, on the world time zone map:

Blue - Brazilian time (southern and capital) in the UTC/GMT-2 zone in the summer (November-March) in the Southern Hemisphere (in winter (April-October) - UTC/GMT-3);

Blue - UTC/GMT-2 zone in the oceans;

Bright yellow - the Atlantic islands of Brazil and the Antarctic islands of Great Britain - UTC/GMT-2 zone all year round;

Orange - UTC/GMT2 zone in summer (April-October) in the Northern Hemisphere;

Azores Standard Time

AZOST - Azores Standard Time - corresponds to GMT -1;

GMT time is on the Greenwich meridian. Determined by astronomical observations of the daily movement of stars - GMT +00, it corresponds to Dublin, Edinburgh, Lisbon, London, Casablanca, Monrovia;

CET

Central European Time (CET) is one of the names for the UTC+1 time zone. Some European and North African countries take advantage of this time. Most of them also use Central European Summer Time (CEST) UTC+2 as their summer time. In a narrower sense, Central European time means the time system in those countries and territories of Europe (Amsterdam, Berlin, Bern, Brussels, Vienna, Copenhagen, Madrid, Paris, Rome, Stockholm), Belgrade, Bratislava, Budapest, Warsaw, Ljubljana, Prague , Sarajevo, Skopje, Zagreb),

EET

Eastern European Time (EET) is one of the names for the UTC+2 time zone. Some European, North African and Middle Eastern countries take advantage of this time. Most of them also use Eastern European Summer Time (EEST) as their summer time. In a narrower sense, Eastern European time means the time system in those countries of Eastern Europe (Athens, Bucharest, Vilnius, Kiev, Chisinau, Minsk, Riga, Sofia, Tallinn, Helsinki, Kaliningrad), Egypt, Israel, Lebanon, Turkey, South Africa;

Moscow time

Moscow time (MSK) is time of the time zone in which the capital of the Russian Federation, the city of Moscow, is located (as defined in the Federal Law “On the Calculation of Time”). Operates in most regions of the European part of Russia. From October 26, 2014 corresponds to UTC+3, from March 27, 2011 to October 25, 2014 corresponds to UTC+4.

Samara time

Samara Time (SAMT) is the unofficial name of the local time of the time zone in which the city of Samara is located - the administrative center of the Samara region. Samara time differs by +4 hours from UTC (UTC+4) and by +1 hour from Moscow time (MSK+1). This is the official time in the Samara region and Udmurtia.

GMT +4 - Samara time.

GMT +4 also operates in the United Arab Emirates, Oman, Azerbaijan, Armenia, Georgia;

Yekaterinburg time

Ekaterinburg time (Russia Time Zone 4, RTZ 4, YEKT, sometimes Ural time) is the unofficial name of the local time of the time zone in which the city of Yekaterinburg is located - the administrative center of the Sverdlovsk region.

Time zone MSK+2 (currently - GMT +5, until 2014 - GMT+6, until 2011: in winter - GMT+5, in summer - GMT+6). This is the official time in Bashkortostan, Perm Territory, Kurgan, Orenburg, Sverdlovsk, Tyumen, Chelyabinsk regions, Khanty-Mansiysk and Yamalo-Nenets Autonomous Okrug.

GMT +5 also applies to regions with Western Asian time (Islamabad, Karachi, Tashkent);

Omsk time

Omsk time (OMST) is the unofficial name of the local time of the time zone in which the city of Omsk is located - the administrative center of the Omsk region. Omsk time is 6 hours ahead of UTC (UTC+6) and 3 hours ahead of Moscow time (MSK+3). This is the official time in the Omsk region and in most regions of Western Siberia (as of 2014). Sometimes Omsk time is called “Novosibirsk time”.

Also GMT +6 applies to Bangladesh, Kazakhstan), Sri Lanka;

Krasnoyarsk time

Krasnoyarsk time (KRAT) is the unofficial name of the local time of the time zone in which the city of Krasnoyarsk is located - the administrative center of the Krasnoyarsk Territory. Krasnoyarsk time differs by +7 hours from UTC (UTC+7) and by +4 hours from Moscow time (MSK+4). This is the official time in four Siberian regions of Russia: Krasnoyarsk Territory, Kemerovo Region, Khakassia and Tuva.

GMT +7 operates in Southeast Asia (Bangkok, Jakarta, Hanoi);

Irkutsk time

Irkutsk Time (IRKT) is the unofficial name of the local time of the time zone in which the city of Irkutsk is located - the administrative center of the Irkutsk region. Irkutsk time differs from Moscow time by +5 hours (MSK+5). Currently it corresponds to the time zone GMT+8, until October 26, 2014 it corresponded to GMT+9, until March 27, 2011 it corresponded to GMT+8 in winter, and GMT+9 in summer. This is the official time in three East Siberian regions of Russia: Irkutsk region, Buryatia and Transbaikal region. The Trans-Baikal Territory switched to Irkutsk time on October 26, 2014. Before this, the region lived according to Yakut time.

In addition, similar time (GMT+8) is common in China, Hong Kong (Hong Kong), Macao (Macau), central and eastern Mongolia, the Philippines, Malaysia, Western Australia (Perth), central Indonesia (eastern Kalimantan, Sulawesi and etc.), Singapore, Brunei;

Yakut time

Yakut time (YAKT) is the unofficial name of the local time of the time zone in which the city of Yakutsk is located - the capital of the Republic of Sakha (Yakutia). Yakut time differs by +9 hours from GMT (GMT +9) and by +6 hours from Moscow time (MSK+6). This is the official time in the Amur region and in the western and central parts of Yakutia, including Yakutsk.

In addition, similar time (GMT+9) is used year-round in Korea (DPRK and the Republic of Korea), Japan, eastern Indonesia (West Papua), East Timor and Palau;

Vladivostok time

Vladivostok Time (VLAT) is the unofficial name of the local time of the time zone in which the city of Vladivostok is located - the administrative center of the Primorsky Territory.

Vladivostok time differs by +10 hours from GMT (GMT+10) and by +7 hours from Moscow time (MSK+7). This time is in a number of East Siberian and Far Eastern regions of Russia: in the mid-northern and mid-eastern parts of Yakutia, in the Primorsky and Khabarovsk territories, in the Jewish Autonomous Region in the Magadan and Sakhalin regions (on Sakhalin Island and the southern part of the Kuril Islands[). There is no seasonal clock change.

In addition, the same GMT +10 time applies to Brisbane, Canberra, Melbourne, Sydney), Tasmania, Western Pacific Time (Guam, Port Moresby);

Middle Kolyma time

Middle Kolyma Time (SRET) is the unofficial name of the local time of the time zone in which the city of Srednekolymsk is located - the administrative center of the Srednekolymsky ulus of the Republic of Sakha. Central Kolyma time differs by +11 hours from GMT (GMT+11) and by +8 hours from Moscow time (MSK+8). This is the official time in the northeastern part of Yakutia and the northern Kuril Islands. Until October 26, 2014, GMT+11 time (during the period of summer time and “permanent summer time” 2011-2014 - GMT+12) was called Magadan time, as it was valid in the Magadan region. In 2010-2014, it also operated on the territory of the Kamchatka Territory and the Chukotka Autonomous Okrug, and was the easternmost time zone of Russia.

This time zone also extends to the Solomon Islands, New Caledonia;

Wellington time zone

Wellington is the capital of New Zealand, the second most populous city in the country, the largest capital among the countries of Oceania and the southernmost capital in the world. The city is located in the Wellington region in the southern part of the North Island. The Maori name for Wellington is Te Fanawi-a-Tara. City area: 290 km². Wellington population: 431,400 (2007). Coordinates: 41°17′20″ S w. 174°46′38″ E. d. Time zone: GMT +12.

Time zones of Russia according to GMT

The territory of our country is very large and therefore there are as many as nine time zones in Russia. Each of us has heard the expression that when Muscovites wake up, those in the Far East are already going to bed. This happens because these two cities are located in different parts of the country and live in different time zones with the maximum difference.

Time zones of Russia

Moscow time is considered the main time - in Moscow the departure of trains from stations in all cities is announced, in Moscow time television announcers inform us about the screening of films. All other regions must calculate the difference between Moscow and local time independently.

There are a huge number of time zone maps, they are compiled for the convenience of people. By looking at such a map, you can clearly see what time zone you live in and what the difference is between your local time and, for example, Moscow. Therefore, there is no need to keep in mind information about the time zones of Russia or another country. You can open the desired page of the site at any time and find out all the information that interests us.

Russia was not among those states that adopted the division into time zones in 1884. The scientist-astronomer Otto Struve, who represented our country at the World Meridial Conference, reporting on the meeting, negatively assessed the project of dividing into belts. And in Russia everything remained the same, the determining factor was solar time. The tsarist government did not dare to change anything in this matter. However, the revolution of 1917 changed not only the state of Russian society, but also the current times. A few months after the October coup, the Council of People's Commissars issued a decree that approved the zone division - for a uniform time count with the entire civilized world, which should greatly simplify relations between peoples, the registration of events and phenomena in time. The country was first divided into 11 time zones, their borders drawn almost everywhere along the meridians.

Moscow time zone (in winter): +3 (GMT + 3:00).

Moscow time zone (summer time): +4 (GMT + 4:00)

On the territory of Russia, since March 28, 2010, there are 9 time zones (before that there were 11 time zones). From March 21 to March 29, 2014, on the territory of Russia there were no longer 9 time zones, but 10. This was due to the inclusion of the Autonomous Republic of Crimea and the city of Sevastopol into the Russian Federation, which previously used Eastern European time, which at that time coincided with the time UTC/GMT+2. On March 17, 2014, the government of the Republic of Crimea adopted a decree on the transition to Moscow time from March 30, 2014. On March 30, 2014, the Republic of Crimea and Sevastopol switched to Moscow time UTC/GMT+4

On July 1, 2014, the State Duma adopted a Law that introduces 11 time zones in Russia from 2:00 am on October 26, 2014.

1st time zone of Russia (MSK-1, UTC+2)

The 1st time zone (MSK-1, Moscow time minus 1 hour, UTC+2) is the Kaliningrad region.

2nd time zone of Russia (MSK, UTC+3)

2nd time zone (MSK, Moscow time, UTC+3) - the Republic of Adygea, the Republic of Dagestan, the Republic of Ingushetia, the Kabardino-Balkarian Republic, the Republic of Kalmykia, the Republic of Crimea, the Karachay-Cherkess Republic, the Republic of Karelia, the Komi Republic, the Republic of Mari El, Republic of Mordovia, Republic of North Ossetia - Alania, Republic of Tatarstan, Chechen Republic, Chuvash Republic, Krasnodar Territory, Stavropol Territory, Arkhangelsk Region, Astrakhan Region, Belgorod Region, Bryansk Region, Vladimir Region, Volgograd Region, Vologda Region, Voronezh Region, Ivanovo region, Kaluga region, Kirov region, Kostroma region, Kursk region, Leningrad region, Lipetsk region, Moscow region, Murmansk region, Nizhny Novgorod region, Novgorod region, Oryol region, Penza region, Pskov region, Rostov region, Ryazan region, Saratov region , Smolensk region, Tambov region, Tver region, Tula region, Ulyanovsk region, Yaroslavl region, federal cities of Moscow, St. Petersburg, Sevastopol and Nenets Autonomous Okrug.

3rd time zone of Russia (MSK+1, UTC+4)

The 3rd time zone (MSK+1, Moscow time plus 1 hour, UTC+4) is the Udmurt Republic and the Samara region.

4th time zone of Russia (MSK+2, UTC+5)

The 4th time zone (MSK+2, Moscow time plus 2 hours, UTC+5) is the Republic of Bashkortostan, Perm Territory, Kurgan Region, Orenburg Region, Sverdlovsk Region, Tyumen Region, Chelyabinsk Region, Khanty-Mansiysk Autonomous Okrug - Yugra and the Yamalo-Nenets Autonomous Okrug.

5th time zone of Russia (MSK+3, UTC+6)

The 5th time zone (MSK+3, Moscow time plus 3 hours, UTC+6) is the Altai Republic, Altai Territory, Novosibirsk Region, Omsk Region and Tomsk Region.

6th time zone of Russia (MSK+4, UTC+7)

The 6th time zone (MSK+4, Moscow time plus 4 hours, UTC+7) includes the Republic of Tyva, the Republic of Khakassia, the Krasnoyarsk Territory and the Kemerovo region.

7th time zone of Russia (MSK+5, UTC+8)

7th time zone (MSK+5, Moscow time plus 5 hours, UTC+8), it includes the Republic of Buryatia, Trans-Baikal Territory and Irkutsk region.

8th time zone of Russia (MSK+6, UTC+9)

The 8th time zone (MSK+6, Moscow time plus 6 hours, UTC+9) includes the Republic of Sakha (Yakutia) (in particular, ulutsy (districts): Aldansky (Aldan city), Amginsky (Amga village) . Lensky (Lensk), Megino-Kangalassky (Nizhny Bestyakh), Mirninsky (Mirny), Namsky (Namtsy village), Neryungrinsky (Neryungri), Nyurbinsky (Nyurba), Olenyok national (Olenyok village) ), Olekminsky (Olyokminsk), Suntarsky (Suntar village), Tattinsky (Ytyk-Kyuyol village), Tomponsky (Khandyga village, Ust-Aldansky (Borogontsy village), Ust-Maisky (Ust-Maya village), Khangalassky (city of Pokrovsk), Churapchinsky (village of Churapcha), Eveno-Bytantaysky National (village of Batagai-Alyta), urban districts of Yakutsk and Zhatai) and Amur region.

9th time zone of Russia (MSK+7, UTC+10)

The 9th time zone (MSK+7, Moscow time plus 7 hours, UTC+10) is the Republic of Sakha (Yakutia) (Verkhoyansk, Oymyakon and Ust-Yansky uluses), Primorsky Territory, Khabarovsk Territory, Magadan Region, Sakhalin Region ( except for the North Kuril region) and the Jewish Autonomous Region.

10th time zone of Russia (MSK+8, UTC+11)

The 10th time zone (MSK+8, Moscow time plus 8 hours, UTC+11) is the Republic of Sakha (Yakutia) (Abyisky, Allaikhovsky, Verkhnekolymsky, Momsky, Nizhnekolymsky and Srednekolymsky uluses), Sakhalin region (only North Kuril region ).

11th time zone of Russia (MSK+9, UTC+12)

The 11th time zone (MSK+9, Moscow time plus 9 hours, UTC+12) includes the Kamchatka Territory and the Chukotka Autonomous Okrug.

International Time Format Standard ISO 8601

ISO 8601 is an international standard issued by ISO (International Organization for Standardization) that describes the date and time format and provides guidelines for its use in an international context. Name of the norm - Data elements and interchange formats - Information interchange - Representation of dates and times.

The first edition of ISO 8601 was published in 1988 and consolidated and replaced a number of older ISO standards dealing with the representation of date and time: ISO 2014, 2015, 2711, 3307 and 4031. In 2000, the standard was replaced by a second edition and, more recently, in 2004 by the current third edition of ISO 8601:2004 (English), published on December 3, 2004.

The standard uses the Gregorian calendar, which serves as the international standard for civil use. Time zones in ISO 8601 are represented as local time (with no location specified) as UTC, or as an offset from UTC.

If no UTC relation information is given with the time representation, the time is assumed to be in local time. While it may be safe to assume local time when communicating in the same time zone, it is ambiguous when used in communication across different time zones. It is usually preferable to indicate the time zone (zone indicator) using a standard notation.

If the time is in UTC, add Z directly after the time without space. Z is the zone indicator for UTC zero offset. "09:30 UTC" is therefore represented as "09:30Z" or "0930Z". "14:45:15 UTC" would be "14:45:15Z" or "144515Z". Observable periodically repeating processes of the same duration have long been used to measure time. The easiest and most convenient way was to monitor astronomical phenomena. For example, solar time was determined by changes in the hour angle of the Sun, and stellar time was determined by the daily rotation of the Earth relative to the stars.

Other systems and time scales

Observable periodically repeating processes of the same duration have long been used to measure time. The easiest and most convenient way was to monitor astronomical phenomena. For example, solar time was determined by changes in the hour angle of the Sun, and stellar time was determined by the daily rotation of the Earth relative to the stars.

However, scientific and technological progress required convenient and accurate units of time, based on a stable periodic natural process. In addition, there was a need for a time counting system (time scale). Depending on the periodic process used, solar, sidereal, dynamical and atomic time scales are currently defined and used.

Using a time scale to determine the accuracy of the duration of a second

Ephemeris time, ET

The uniformly current time is the ephemeris time ET (Ephemeris Time), the unit of which is the ephemeris second. The ephemeris time scale is set by the orbital motion of the bodies of the Solar System, and the ephemeris time is determined from long-term astronomical observations of them. When calculating their positions, ephemeris time is used, and when observing, universal time is used, so the difference between ephemeris and universal time can be calculated. Unfortunately, the exact difference between ephemeris and universal time can be determined with great delay, based on phenomena that occurred in the past.

Since 1986, the ephemeris time scale ET has been replaced by two dynamic time scales DT - terrestrial dynamic time TDT and barycentric dynamic time TDB:

Earth's dynamic time TDT, equal in scale to ET, is related to the Earth's center of mass and serves as an independent argument for visible geocentric ephemerides, including when determining satellite ephemerides;

Barycentric dynamical time TDB, which takes into account the movement of the center of mass of the Sun around the center of mass of the entire Solar System (barycenter of the Solar System). Referred to as the barycenter of the Solar System and is an argument for the differential equations of all gravitational theories of the motion of bodies in the Solar System. Ephemeris time is usually denoted by (ET). And it is defined using Universal Time (UT) as follows:

Atomic time, TAI

The development of molecular and atomic frequency standards led to the emergence of a fundamentally new atomic time scale, TAI (Time Atomic International), independent of the rotation of the Earth and the movement of bodies in the Solar System. At the XIII International Conference on Weights and Measures (1967) it was recommended for one time - second - take "a duration of 9 192631 770 oscillations of radiation corresponding to the resonant frequency of the transition between two levels of the hyperfine structure of the ground state of the cesium-133 atom, in the absence of disturbances from external fields." The duration of an atomic second is as close as possible to the duration of an ephemeris second.

The TAI scale is formed in the French Bureau International des Poids et Measures (BIPM) based on averaging the readings of individual atomic clocks located in various institutes and laboratories around the world. To synchronize atomic clocks, special radio time signals, the Internet and global navigation systems (GPS) are most often used. and GLONASS).

Universal Time or UT (Universal Time) is a time scale based on the rotation of the Earth. Universal Time is the modern replacement for Greenwich Mean Time (GMT), which is now sometimes incorrectly used as a synonym for Coordinated Universal Time (UTC). Universal Time was introduced on January 1, 1925. In fact, the term "universal time" is ambiguous, as there are several versions of universal time, the main ones being UT1 and UTC.

All versions of universal time are based on the rotation of the Earth relative to distant celestial objects (stars and quasars), using a zoom factor and other adjustments to be closer to solar time.

However, despite the high accuracy of such clocks, the need for universal time, determined from the results of astronomical observations, has not disappeared, and several systems of the universal time scale are used to solve certain problems:

UT0 is universal time, obtained directly from astronomical observations and depending on the position of the observation point on the Earth's surface;

UT1 - universal time obtained taking into account the calculated corrections for changes in the longitudes of observation points due to the movement of the Earth's poles;

UT2 is universal quasi-uniform time (quite uniform over several years), obtained taking into account seasonal variations in the Earth’s rotation speed calculated based on studies of previous years.

Time of satellite navigation systems

GPS Time System (TGPS) is Coordinated Universal Time (UTC), referenced to the beginning of 1980. TGPS corrections to UTC are recorded with high accuracy and are transmitted as a constant value in the navigation message, and are also published in special bulletins.

GPS satellites have highly stable frequency standards, on the basis of which their own atomic scale is formed, which is called TAI (GPS). GPS time differs from UTC by an integer number of leap seconds. This is because the GPS time scale starts from January 6, 1980. At the end of 2004, the difference was 13 seconds. The integer number of seconds of difference is included in the broadcast GPS signal and then automatically processed by the GPS receiving equipment so that the time displayed by the GPS equipment is the same as UTC coordinated time. There is, however, a continuously varying small difference, which is almost always less than 25 ns.

Sources and links

Sources of texts, pictures and videos

ru.wikipedia.org - a resource with articles on many topics, a free encyclopedia Wikipedia

youtube.com - YouTube, the largest video hosting in the world

geographyofrussia.com - physical geography, what is a time zone?

infoknyga.lt - information book, what is a time zone?

loco.ru - articles on the site, time zones, Greenwich Mean Time, UTC, CDT

subsidii.net - news site, clock change in Russia

world-time-zones.ru - time zones, Russian time zones

phcode.ru - telephone codes of Russia, time zones of Russia

liveinternet.ru - quote book, time: world time zones - Greenwich Mean Time

pam65.ru - time portal, who needed time zones

travel-child.ru - Royal Observatory Greenwich and the Greenwich meridian

library.kiwix.org - articles on the site, Greenwich Observatory

tisamsebegid.ru - information portal about tourism and travel, Royal Observatory (Greenwich)

usaamerica.info - news site about America, time in the USA

gmt.su - Greenwich time, time in cities around the world

ru.thetimenow.com - Greenwich Mean Time (GMT)

bugaga.ru - articles on the site, 10 Little-Known Facts about Time Zones

krasoteurop.ru - blog for tourists, Greenwich - the place where time begins

24timezones.com - time zone directory, time zones of the world

otherreferats.allbest.ru - bank of abstracts, time zones of the Earth

bestreferat.ru - bank of abstracts, time zones of the Earth

sav-files.narod.ru - World time zones and their offsets from UTC/GMT (Greenwich Time)

kakras.ru - directories, time zones UTC, GMT

ruqrz.com - articles on the site, exact time and frequency

planetolog.ru - world maps, Canadian time zones

ru.translate.net - time zones, time zone of Iceland

kakprosto.ru - articles on the site why the time zone is called GMT

ru.knowledgr.com - new knowledge, Greenwich Mean Time

library.kiwix.org - material from Wikipedia, ephemeris time

studopedia.ru - studopedia, atomic time

wiki.dieg.info - IT working notes, Greenwich Mean Time

mirastronomii.ru - entertaining astronomy, Greenwich Time

rasvetsiriusa.com - articles on the site, time zones

nteresnoe.info - a little about everything interesting, current time in Russian cities

Links to Internet services

forexaw.com - information and analytical portal on financial markets

google.ru - the largest search engine in the world video.google.com - video search on the Internet using Google

translate.google.ru - search engine translator

Google yandex.ru - the largest search engine in Russia

video.yandex.ru - search for videos on the Internet via Yandex

images.yandex.ru - image search through the Yandex service

Application links

windows.microsoft.com - website of Microsoft Corporation, which created the Windows OS

office.microsoft.com - website of the corporation that created Microsoft Office

chrome.google.ru - a frequently used browser for working with websites

hyperionics.com - website of the creators of the screenshot program

HyperSnap getpaint.net - free image manipulation software

Article creator

vk.com/id238040329 - profile in VKontakte

odnoklassniki.ru/profile/236293636061 - profile on Odnoklassniki

facebook.com/profile.php?id=100008317868136 - Facebook profile

twitter.com/goldcoin7777 - Twitter profile

plus.google.com/111295713717655619651/posts - profile on Google+

hellenker4rus.livejournal.com - blog on LiveJournal

Its time zone 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.

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 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 must be counted 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.

Until now, in Windows computer settings, the time zone is specified by the abbreviation GMT. What is this and how does it relate to the modern UTC time coordination system? We will talk about this in our article. not everyone can do it at their location relative to Greenwich. But we will try to explain this issue in popular language. First of all, you need to answer the question: “What is GMT?” How does this abbreviation stand for?

British snobbery

In the old days, 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 day. With the development of international trade, the need arose to coordinate time into a single system. The starting point was He passes through the Royal Observatory in the town of Greenwich, near London.

Thus, the abbreviation GMT stands for Greenwich Mean Time. All the territories that are to the west of Greenwich are behind his time, and those that are located to the east are ahead of him. There is another significant meridian on the surface of planet Earth. This Territory, located to the east of it, lives (in the truest sense of the word) yesterday. In 1972, the new abbreviation UTC replaced GMT. What time is this? The abbreviation stands for Coordinated Universal Time.

Time Zones

In Russian-language metrology, the abbreviation SGV is used instead of GMT. What is it? The letters stand for “Mean Geographic Time.” But again, we can’t escape Greenwich. After all, the whole world counts its clock from the prime meridian. If you are 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. And Coordinated Universal Time (in other words, UTC) basically displays noon in certain countries (or parts thereof). If GMT is a time that does not know political boundaries, then time zones often extend to an entire state (if it does not extend very far from west to east). Thus, UTC+0 is the time not in and on the prime meridian, but throughout Great Britain and Ireland, as well as Iceland, Portugal, Morocco, etc. But the calculation of hours using the UTS system is carried out on the same principle as in GMT .

Summer and winter time

In countries at high latitudes, the length of daylight varies greatly depending on the time of year. Therefore, northern countries often switch to summer time. Residents of these countries move their clocks forward an hour. This happens on the last Sunday of March. The UK is also on the list of countries that practice summer clocks. But true noon from April to October is then observed at 1 pm, because Greenwich Mean Time does not depend on the season.

Countries lying near the equator, where at any time of the year there is approximately twelve hours, do not move the hands seasonally. They constantly live according to winter (true) time. On this basis, the Russian Federation decided not to move the hands forward an hour every year. By the way, another country located at high latitudes refused to switch to summer time. This is Iceland. The island nation operates according to Greenwich Mean Time (GMT+0). Great Britain and Ireland, which lie on approximately the same meridian, are at UTC+0 in winter and UTC+1 in summer.

What are UTC and GMT for?

Time is a concept that loves precision. For coordinated actions, dispatch services located at points of the Earth remote from each other need to know what hours, minutes and seconds it is. Radio broadcasters of different frequencies also need coordinated time. UTC is necessary to establish a certain standard for navigational and scientific purposes. Throughout the nineteenth century, sailors of the British fleet, sailing the world's oceans, calculated time using GMT. Moving west of Greenwich, they took away hours, and moving east, they added hours. According to this principle, it is now divided into time zones. For example, Vladivostochnaya time corresponds to GMT+11, Georgian - GMT+4, Hawaiian-Aleutian - GMT-10, Moscow - GMT+4, Standard Eastern Time (it is used for New York and the territories adjacent to the Atlantic Ocean of the USA and Canada, and also in Jamaica, Panama, Haiti, Bahamas) - GMT-5.

We recommend reading

SERB, NOD and "Forty Forties"

The attack on Alexei Navalny on April 27, as a result of which he was...

How to submit a notice of deregistration as a trade duty payer?

Today the legislation is structured in such a way that practically...

A controlled transaction - what is it and who sells it?

Tax Code, N 146-FZ | Art. 105.14 Tax Code of the Russian Federation Article 105.14 Tax Code of the Russian Federation....

What does Greenwich mean? What is UTC or Greenwich Mean Time? GMT is the definition

Table - time zones of cities around the world (UTC/GMT), in the summer

Terms and Definitions

How to use the time calculator?

time, which in Russian meteorological terminology sounds like Greenwich Mean Time or geographic time, which got its name due to the meridian passing through the Royal Observatory located in Greenwich

GMT is the definition

The history of the appearance of geographic time GMT

The first four countries to adopt GMT (1848-1883)

Transition to Greenwich Time in different parts of the world (1994-1905)

France's transition to GMT time (1996-1911)

Countries that were the last to adopt the GMT system (1912-1972)

Royal Observatory Greenwich and the Greenwich Meridian

General characteristics of Greenwich time

Universal Time (UT)

Greenwich Mean Time

Greenwich Mean Time

Transition to summer and winter time GMT

Daylight saving time in Russia

Disagreements between legal and geographical criteria for GMT time

How to determine Greenwich time?

Why is the time zone called GMT?

Time zones of cities and countries around the world according to Greenwich Mean Time (UTC/GMT)

Samoa time zone

Time zone in Hawaii

Alaska time zone

US Pacific Time

Mountain Time USA

US Central Time

US Eastern Time

South American Pacific Time

Atlantic Standard Time

South American Eastern Time

Time zone in Greenland

Mid-Atlantic time

Azores Standard Time

CET

EET

Moscow time

Samara time

Yekaterinburg time

Omsk time

Krasnoyarsk time

Irkutsk time

Yakut time

Vladivostok time

Middle Kolyma time

Wellington time zone

Time zones of Russia according to GMT

1st time zone of Russia (MSK-1, UTC+2)

2nd time zone of Russia (MSK, UTC+3)

3rd time zone of Russia (MSK+1, UTC+4)

4th time zone of Russia (MSK+2, UTC+5)

5th time zone of Russia (MSK+3, UTC+6)

6th time zone of Russia (MSK+4, UTC+7)

7th time zone of Russia (MSK+5, UTC+8)

8th time zone of Russia (MSK+6, UTC+9)

9th time zone of Russia (MSK+7, UTC+10)

10th time zone of Russia (MSK+8, UTC+11)

11th time zone of Russia (MSK+9, UTC+12)

International Time Format Standard ISO 8601

Other systems and time scales

Ephemeris time, ET

Atomic time, TAI

Time of satellite navigation systems

Sources and links

Sources of texts, pictures and videos

Links to Internet services

Application links

Article creator

British snobbery

Time Zones

Summer and winter time

What are UTC and GMT for?

We recommend reading

Site search