How many meridians are included in a time zone? Terms and Definitions

There are only 24 time zones in the world.

The boundaries of time zones can run along major rivers, along administrative boundaries and along interstate borders.

The starting point for the belts is the Greenwich meridian; the belts are counted from west to east.

Quite officially, planet Earth is divided into 24 time zones, these are the so-called geographical zones, the time difference between which is one hour. It is easy to calculate that there should be 24 such belts - exactly as many as there are hours in an earthly day. However, in addition to geographical time zones, there are also administrative zones, determined not by the boundaries of the meridians, but by the geographical features and position of the countries. There are significantly more such zones - 40. This difference is caused by the presence of half time zones, the time in which differs from the neighboring zone not by an hour, but by 30 minutes. This is, for example, India with a time zone of +5:30 or Newfoundland with a time of -3:30. In addition, there are very original places where the time differs from the global time by 45 minutes - these are Nepal, several cities in Australia and the Chatham Archipelago. the latter, by the way, is the only object in the world that has two different time zones that do not coincide with other time zones - summer and winter +12:45 and +13:45.

Time Zones Some are geographical and some are administrative. Total There are 24 time zones in the world, according to the number of hours in a day. Administrative time zones, for the most part, coincide with geographic ones, but may depend on regional boundaries and decisions of national governments. Geographic time zones are always constant and are measured from the Greenwich meridian, which is considered the zero time zone.

There are 11 geographical time zones in Russia, but President Medvedev decided that it would be too much and reduced their number to 9 administrative ones, so as not to frighten our Western partners with the enormity of Russia, whose entire country fits into one time zone.

Time zones in the world twenty four, as many as there are hours in one day. On one part of the globe it may be morning, on another part it may be night.

Here are countries with two or more time zones:

Once upon a time I had to travel around Russia a lot on business, sometimes it’s not so easy to get used to a new time zone, especially when it varies a lot in the time zone.

Actually, the answer follows from the question itself: for the convenience of navigation, aviation and simply the life of citizens, there are exactly the same number of time zones in the world as there are hours in a day. Very exotic sentries in Kabul and Nepal - the guys prefer to walk slowly

There are 24 time zones in the world. The location of the belts depends on the administrative boundaries of the states. Detailed belt map and educational film here: http://jerusalemtour.ru/chasovy-e-poyasa-mira/

There are 24 time zones in the world, which is exactly the number of hours in a day. If there were, for example, 30 zones in the world, then our day would last 30 hours (well, this is purely my guess, maybe I don’t understand something).

There are 24 time zones in the world and that is exactly how many dividing lines are drawn along the surface of the globe. But only in places is this line even. As a rule, time zone boundaries bend and even sometimes intertwine in accordance with the boundaries of states and decisions made by the governments of those states. Although time is a completely objective thing, its calculation is a subjective thing and depends on agreements between people.

There are 24 time zones in the world, as you might guess. That is, if you look at the globe, then exactly 24 medians are drawn across it, each median is a time zone. I know that Moscow time is +4, and Hawaii is -10.

There are only twenty-four time zones in the entire world (the conventional division of the earth).

In Russia, until recently, for example, there were 9 time zones (at one time they were reduced), but this year, 2014, there were 11 time zones again. The country is big, so this is not surprising. Other countries, for example in Europe, all fit into just one time zone.

There are only twenty-four time zones in the world, logically they didn’t sell it, why? Since it was accepted, but not without reason, the Greenwich meridian was accepted as the zero meridian, and then from left to right, such a division is connected with taking into account the speed of rotation of the earth. That is, at 12 noon it’s day for everyone.

The clock will show different times depending on your location on the planet. Our entire globe was divided into 24 time zones, each with an hour in the day. As a matter of fact, an hour is the difference between two neighboring zones.
The change of zones is determined by meridians located 15 degrees from each other in longitude. But how many time zones are there in Russia?

Calculate how many time zones there are in Russia?

Sometimes in a state, for convenience, capital time is taken as local time, although formally the country is located in several time zones. But in huge countries like the USA or Russia, this simplification will not work. Therefore, we have to put up with time separation. And if in America there are 5 time zones, then in the Russian Federation there are 9.

How did time zones come about?

The idea to introduce time zones came from Sandford Fleming, a resident of Canada. But at first his idea was angrily rejected by the world community. However, Fleming was persistent and launched an entire campaign in support of his idea. And so, in 1884, the International Meridial Conference took place. By that time, only the lazy did not talk about Fleming’s proposal, so the resolution on the belts was nevertheless adopted. And then midnight began to be considered the beginning of the day, and before that time, by the way, the day began exactly at noon.

And although by 1929 all countries had adopted the resolution, not all issues had been resolved in time.

Also an interesting fact: the Russian Empire did not support the international belt system then, in 1884. They were introduced in Russia only after the 1917 revolution. And at first Russia was divided into 11 zones. And only in 2010, two of them were abolished in accordance with the law “On the Calculation of Time”. So, in Yakutia, which lies in three time zones, there is now one time. And Moscow became the starting point. So, moving from the capital to the east, add time. To the west - take it away.

Different meridians have different times of day at the same moment. For example, if it is noon on the zero meridian, then at the same time on the 180th it is midnight, at 90 east. evening, and at 90 west. morning. The day begins simultaneously on the entire meridian, each meridian has its own local time, it depends on longitude, the further east the meridian is, the earlier the day begins on it. The 180th meridian is considered to be the international date line. From there to the west, each new day on Earth is counted. Therefore, the first in our country and in the world to celebrate the New Year and every new day are the residents of Chukotka, then Kamchatka, etc. to the west.

Definition of local time: rotating, the Earth describes a circle of 360 in 24 hours, i.e. The earth rotates 15 degrees every hour; if the distance between the meridians is 1 degree, then the time difference between them will be 4 minutes.

Determine the local time in Vladivostok if it is noon in St. Petersburg (Vladivostok is further east, so the day starts earlier there (12 hours + 6 hours 48 minutes = 18 hours 48 minutes). Therefore, the local time of Vladivostok is 18 hours 48 minutes if in St. -Petersburg noon.

In practical life, local time is usually not used due to significant time differences even between neighboring points. Therefore, standard time was introduced throughout the world back in the 19th century.

Rules for drawing the boundaries of time zones and how many there are on the surface of the globe

Time zone boundaries are broken lines.

For the convenience of counting the current time, the entire territory of the globe is divided into 24 time zones. Within each such zone, its own single standard time is established. The width of the time zone is 15° longitude. The initial (first) belt is considered to be the one through the middle of which the prime (Greenwich) meridian passes. In reality, on land, the boundaries of time zones do not follow meridians, but along the state borders of various countries close to them. For large countries that fall into several time zones, the border between these zones usually runs along the boundaries of the internal administrative-territorial division of these countries. The territory of the Union of Independent States is located in time zones from the third to the thirteenth inclusive.

The difference between time zone numbers corresponds to the time difference between these zones. However, in reality, determining local time in other countries is not so simple. The difficulty here is that on the territory of a number of countries it is not standard time that operates, but so-called maternity time, which differs from standard time by a certain constant value. For example, in India, which is mainly located in the sixth time zone, a single time is adopted, the difference of which with the first time zone is set at 5 hours 30 minutes. Another example is the CIS, where throughout the entire territory the hour hand is moved 1 hour compared to standard time.

Another difficulty in determining local time is caused by the fact that in many countries (including the CIS), in order to more fully use the daylight hours and save energy, “winter” time is in effect for part of the year, and “summer” for the other part of the year. ". The transition from “winter” time to “summer” usually occurs in March-April (and in different countries this takes place on different days), and the reverse transition occurs in September-October. When switching to “summer” time, the clock hands are shifted one hour ahead compared to “winter” time.

Thus, for example, in Moscow (third time zone) the time difference with the first time zone is not 2 hours, but either 4 (in summer) or 3 (in winter).

Due to the difficulty of converting one local time to another, in many areas of human activity (in particular radio communications), it was decided to use a single time - universal time. This is the time that corresponds to the prime (Greenwich) meridian and, naturally, the first time zone. For universal time, the designation UT (Universal Time) is accepted, and in the scientific and technical literature the more strict designation UT1 is used. The time scale used in practice in various countries and associated with universal time is called the coordinated time scale and is designated UTC (Universal Time Coordinated).

Time verification signals (six short tone bursts) are transmitted around the clock by many radio stations around the world. This kind of “information” is used by weather services, the marine fleet, airports, and other organizations where time-synchronized work is necessary. Very often such signals can be heard at the end of every hour on air from city VHF radio stations (for example, “Radio Station Mayak”). That is, if the first tone sounds at 14:59:54, then the beginning of the sixth tone corresponds to 15 hours 00 minutes 00 seconds. However, in some cases these signals may not be transmitted if, for example, there is a broadcast of concerts and performances that extend beyond the hour-long time period.

The outdated name for universal time is Greenwich Mean Time (denoted GMT). Sometimes (extremely rarely) the purely amateur radio designation for universal time Z (from the German Zeit) is also found (on QSL receipt cards).

Standard time for some countries

It is inconvenient to use local time in everyday life. When the observer moves along the parallel by 1° of longitude to the east, it is necessary to “move” the minute hand of the clock 4 minutes forward, and when moving by the same amount (by 1° of longitude) to the west, it is necessary to “move” 4 minutes back.

Especially many inconveniences with the local timekeeping system appeared with the development of railway transport. It is enough to note that by 1883, US railroads had 75 different local time systems, which caused great confusion in train schedules.

In 1879, Canadian railway engineer Sandford Fleming proposed the idea of ​​​​introducing standard time, and since 1883 this idea has been adopted in the USA and Canada, and since 1884 it has been officially approved.

According to the standard time system, the entire surface of the Earth is divided into 24 time zones of 15° longitude each(11 – eastern, 11 – western, 1 – zero and 1 – twelfth). Time zones zero and twelve include 7.5° (7°30′) east and west longitudes. The axis of the zero belt coincides with the Greenwich meridian(Fig. 4.8).

Rice. 4.8. Time Zones

The essence of standard time lies in the fact that all observers located in the same time zone have their clocks set according to the local time of the axial (central) meridian of that zone.

Standard time (T N) – this is the local average time of the axial meridian of the belt, distributed throughout the entire belt.

Thus, all time meters on Earth at the same moment should show same number of minutes and seconds, and the number of hours – depending on the time zone number “No” → see table. 4.1.

Table 4.1.

To determine the time zone number (№E/W), it is necessary to divide the observer's geographic longitude by 15°. The integer is quotient and will indicate the time zone number; if the remainder of the division is greater than 7°30′, 1 must be added to the quotient. For example: λ = 38° E ; № = 38°: 15° = 2 + 8° and since 8° > 7°30′, then No. = 3 E .

On the territory of the RSFSR, standard time began to operate on July 1, 1919 and was determined by a special decree of the Council of People's Commissars of February 8, 1919.

“... In order to establish a uniform calculation of time throughout the day with the entire civilized world, which determines the same clock readings in minutes and seconds throughout the entire globe and significantly simplifies the registration of relationships among peoples, social events and most natural phenomena in time...”

Since January 17, 1924 Standard time began to operate throughout the territory of the former USSR.

Since March 1, 1957 New time zone boundaries were established for the territory of the former USSR.

For convenience, time zone boundaries are not drawn strictly along meridians, but are combined with state boundaries, administrative boundaries, water boundaries, mountain ranges, etc.

For example:

The European part of the former USSR lives according to time zone II :

(– Western European time → time “0” time zone;

– Central European time → time “1 E» time zone;

– Eastern European Time → Time “2 E» time zone;

– Moscow time → time "3" E» time zone).

The transition from local time to standard time and vice versa is carried out according to the formula.

When traveling around the world, people inevitably end up at different times of the day - this is due to the movement of the planet around its axis. Russia is a very large country, occupying an impressive territory. For greater convenience, its area was divided into a certain number of zones corresponding to the number of time zones in Russia.

What determines time on Earth?

Our planet, as you know, has a spherical shape. In 24 hours, it manages to make a full revolution around its axis, that is, 360°. Accordingly, in one hour the Earth rotates around its axis by 15°.

In different parts of the world, people experience sunset or sunrise at different times. In places located on different meridians, at the same moment, the clock hands will show different times of day. For example, in Yakutsk it will be 21 hours, while in Yekaterinburg it will be only 17.

But at the same time, on the same meridian along its entire length from the North to the South Pole, the time of day will be the same. This time is called local or solar.

However, using local time is extremely inconvenient: it makes the development of relations between countries very difficult. To eliminate this discomfort, astronomers have proposed introducing a standard time system around the world.

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As a result, the entire planet was divided along the meridians into 24 zones, each of which included 15° longitude. Thus, the time in each time zone differs from the time in neighboring zones by 1 hour.

Zero is considered the time zone in the center of which the Greenwich meridian passes. He is also the 24th in a row. Time zones are counted from zero from west to east.

Rice. 1. Reference point – Greenwich meridian.

Time zones of Russia

The extent of Russia from west to east is very large, covering 11 time zones. The capital of the Russian Federation, Moscow, is located in the second time zone, and, say, the Chukotka Autonomous Okrug is in the twelfth.

Moscow time serves as the reference point for determining local time anywhere in Russia. The difference is calculated by the number of full hours: the count of minutes and seconds is the same in all time zones.

To avoid confusion on the territory of Russia, all work on river, sea, air and railway transport, as well as various types of communications, is carried out only according to Moscow time.

Rice. 2. Time zones of Russia on the map.

For greater convenience, the second and eleventh time zones in Russia were combined into one. For this reason, within the Russian Federation they are encountered not eleven, but ten times.

It’s not difficult to independently calculate the standard time of each individual locality. It is enough to know the boundaries of its location and the number of the time zone in which it is located. For example, if in Moscow, located in the second zone, it is 8 o’clock in the morning, then in Yekaterinburg, located in the fourth zone, it will be 10 o’clock in the morning, since the difference with Moscow will be 2 hours.

Table by city (time difference)

Maternity and summer time

In 1930, by decree of the Council of People's Commissars, clock hands throughout Russia were moved one hour ahead of relative standard time. The country lived in this regime for more than 50 years on the so-called “maternity” time. It was believed that the transition to a new time was established in order to save electricity. The return to seasonal time occurred only in 1981.

In the same year, summer time was introduced on the territory of the USSR. Between April 1 and October 1, clocks across the country were moved forward an hour. The official reason for this transition is the rational use of daylight hours and energy savings.

Rice. 3. Physiologists are against the transition to a new time.

However, physiologists are confident that such jumps in time have a very negative impact on people’s well-being. For any organism, the transition to a new time is stressful, and it takes some time for life cycles to adjust to new conditions.

Daylight saving time in the Russian Federation was canceled in 2011.

What have we learned?

While studying one of the topics in the 8th grade geography program, we found out how many time zones there are in Russia. We found out that their number of time zones corresponds to the number of meridians, and the time difference in each neighboring zone is exactly one hour. Moscow time is considered the main time in Russia, according to which all types of transport operate and connections are established throughout the country.

Test on the topic

Evaluation of the report

Average rating: 4.2. Total ratings received: 593.

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

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)

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.

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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 charging batteries 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.