Standard time definition 8 cells geography. What is local and standard time? What determines time on Earth
Time Zones. In order to regulate the differences in time resulting from the rotation of the Earth on its axis, Earth conditionally divided into 24 time zones . Without them, no one would be able to answer the question: What time is it in other parts of the world?". The boundaries of these belts approximately coincide with the lines of longitude. In each time zone, people set their clocks to their own local time, depending on the point on Earth. The gap between the bands is 15°. In the United States in 1884, Greenwich Mean Time was introduced, which is calculated from the meridian passing through the Greenwich Observatory.
The 180° East and West longitude lines coincide. This common line is called International Date Line. Time at points on the Earth west of this line is 12 hours ahead of time at points east of this line. The time in these neighboring zones coincides, but traveling east you find yourself in yesterday, traveling west you find yourself in tomorrow.
Therefore, in the logbook of a ship that sails from west to east, one day must be counted twice. And a ship moving from east to west, as it were, “misses” one day, after December 31 it immediately falls into January 2.
Local time. standard time
Solar time at points located on the same meridian is called local . Due to the fact that at each moment of the day it is different on all meridians, it is inconvenient to use it. Therefore, by international agreement, standard time . The entire surface of the Earth was divided along the meridians into 24 zones of 15 ° longitude. Belt (the same within each belt) time is the local time of the median meridian of this belt. Zero belt - this is a belt, the median meridian of which is the Greenwich (zero) meridian. From it, the belts are counted to the east.
Time in Russia is regulated by the Federal Law "On the calculation of time", in accordance with which it is established 11 time zones. Moscow time (MSK, MSK) "corresponds to the third time zone in the national time scale Russian Federation UTC (SU) +3". Eleven time zones, from 1st to 11th, correspond to the international numbering of time zones from 2nd to 12th. The boundaries of the time zones pass along the borders of the subjects of the Russian Federation, each subject of the federation is included in one time zone, with the exception of Yakutia, whose territory is located in three time zones (MSK+6, MSK+7, MSK+8). Daylight Saving Time does not apply (seasonal clock changes were canceled in 2011).
Table. Time zones of Russia (2018)
Is it important for everyone to know what time it is in other parts of the world and Russia? Why in Moscow they say: “Good night!”, And at the same time in Vladivostok, a greeting sounds: “Good morning!”. This lesson will help you get an idea of the differences in time in Russia. During the lesson, you will learn how local time differs from standard time, what a "date line" is, how many times a year in Russia you can meet New Year.
Topic: Geographical position of Russia
Lesson: Differences in time in Russia
Our country is stretched from west to east for almost 10,000 km, and this feature geographical location affected the time difference in Russia. (see fig.1)
Rice. 1. The length of Russia from west to east
Day is the natural unit of time. Noon is the highest position of the sun in relation to the point of observation. Noon simultaneously occurs for all points of one meridian - from the North to the South Poles, that is, the time is the same along the entire meridian. This time is called solar time, or local
St. Petersburg, Cairo, Ankara, Harare (Zimbabwe), Pretoria have approximately the same local time, since the longitudes of these settlements differ slightly.
A difference in longitude between two locations of just 1º would provide a difference of 4 minutes between their local time. The earth makes a full 360º rotation in 24 hours, or 1440 minutes, so it rotates 1º in 4 minutes. So the difference in longitudes between Moscow (37 ° E). and St. Petersburg (30° E) is 7º, thus, the local time of these settlements differs by 28 minutes (i.e., by almost half an hour). (see fig.2)
Rice. 2. Differences in local time between Moscow and St. Petersburg
On a relatively large territory, the use of local time in everyday life turns out to be inconvenient: a unified time reference system is needed. For example, having moved from the western outskirts of Moscow to the eastern one, we must set the clock forward one and a half minutes, and having moved from Moscow to St. Petersburg, almost half an hour ago. Therefore, in most countries of the world, a system has been adopted standard time.
It was proposed in 1878 by Canadian engineer Sandford Fleming (see fig.3), which in 1884 was adopted at the International Astronomical Congress in the USA (Washington), where 26 countries were present.
Rice. 3. Sandford Fleming (1827-1915)
According to the idea of S. Fleming, the entire surface of the globe is conditionally divided by meridians into 24 time zones, each 15 ° (1 hour) in longitude. (see fig. 4)
Rice. 4. Time zones ()
At all points of each time zone, the time corresponding to the average meridian of this zone is set. The entire belt lives according to the time of its middle meridian. The difference in time between neighboring meridians (time zones) is exactly 1 hour, and the minute and second hands all over the Earth are the same. The belts are counted in the direction from west to east. Accordingly, when moving from west to east, the hour hand moves forward, from east to west - back.
Rice. 5. Scheme of counting time zones
Belts are indicated by Roman numerals. For the zero one, it is XXIV, the belt is taken, the average meridian of which is the Greenwich meridian. Greenwich time is considered world ( sometimes the term is used - Western European) . (see fig. 6)
Rice. 6. Zero time zone ()
Widespread name Central European time is the time of the I time zone.
The meridian opposite the Greenwich meridian 180° is date line. This line runs from pole to pole along the 180° meridian with some deviations so that it does not cross countries and archipelagos. (see fig. 7)
Rice. 7. Dateline
As already noted, the countdown of time zones starts from the zero (Western European) time zone. Most of the countries of Europe (with the exception of Great Britain and Portugal), as well as the Kaliningrad region of Russia, are located in the I (Central European) time zone. Moscow is in II ( Eastern European) time zone. The standard time of Moscow, the average meridian of which is 30 E lies a little to the west of St. Petersburg, differs by one hour from the Central European one.
Geographically, Russia is located within 11 time zones - from II to XII
(from the extreme western point - the Baltic Spit (19º E) - to Ratmanov Island - the extreme eastern point of Russia (169 W). (See Fig. 8-9). The difference between them is 172 º (172 º: 15 º = 11.5 hours).
Rice. 8. The extreme western point of Russia
Rice. 9. Extreme eastern point Russia
In fact, the difference in time throughout Russia is 9 hours. [L1] For example, when it is 3 pm in Kaliningrad, in Anadyr, Uelen, Petropavlovsk-Kamchatsky- 24 hours.
Rice. 10. Time zones of Russia
On land, the boundaries of time zones, which have a submeridional strike, are drawn not strictly along meridians, but along natural boundaries (mountains, rivers) and administrative boundaries. At the same time, the entire territory of a particular subject of the Russian Federation - republics, territories, regions - turns out to be in the same time zone.
In fact, the time difference between Moscow and, for example, Berlin or Paris is not one, but two hours. This is due to the fact that throughout Russia there is decree time that differs by one hour from standard time.
In 1930, by a resolution (decree) of the government, the hands of the clock were moved one hour ahead compared to standard time. This was done in order to more fully use the daylight hours, and therefore, in order to save electricity. Decree time of the II time zone, where Moscow is located, is called Moscow time.
Since 1981, Russia has been operating from March to September summer time. On the last Sunday in March, the clocks were set one more hour ahead of standard time. Since 2008, the return to standard time usually took place on the last Saturday of October by moving the clock hand back one hour. Since October 2011, there has been no change to winter time.
. Day is the natural unit of time.
Time on a given meridian is called local, and within the time zone - belt.
Due to the large extent of the territory of Russia from west to east, it is located in 11 time zones - from II to XI, but the real difference in time is between two points located on the territory in Russia - 9 hours.
Valid throughout Russia maternity time, which differs from the belt by 1 hour.
Homework
- Determine on the map of time zones () in which time zone is your republic, region, city?
- What changes will occur when crossing the date line from west to east? From east to west?
Standard time was introduced in the United States in 1883. In 1884, in Washington, 26 countries agreed to make the reference point for time zones. Greenwich meridian. And only on July 1, 1919 standard time was introduced in Russia.
Each of the 24 time zones is assigned a corresponding number from 0 (zero) to 23. The zero belt is taken as the middle meridian of which is Greenwich, from which the numbering of the belts is from west to east. The middle meridian of the first belt is 15° east of the Greenwich meridian, or 1 hour in time; the middle meridian of the second zone has an east longitude of 30 °, and its local time differs from the universal (Greenwich) time by 2 hours, etc. Thus, the number of each time zone shows how many whole hours the time of this zone differs from world (ahead of him); at the same time, minutes and seconds in all zones remain the same. Consequently, standard time when moving from one zone to an adjacent zone changes by a jump of 1 hour. If we denote the number of the belt through n, then the standard time is equal to the world time plus n.
If we draw the boundaries of time zones exactly along the meridians, then in the east of the time zone noon will come at 11:30, on the main (middle) meridian - at 12:00, and on the western border of the time zone - at 12:30.
On land, time zone boundaries are drawn along state and administrative borders, so the time of noon in each particular time zone differs slightly from the time interval 11:30 - 12:30.
If the time zone boundary divides a region into 2 parts, then the time of the zone located to the east is usually set here. For example, West Side The Moscow region is located in the II zone, and the eastern - in the third. In 1919, Moscow was assigned to the II belt, although it most of located in III.
In 1930, the clock hands were moved forward 1 hour, the entered time was called maternity leave. Guided by the rules for drawing the boundaries of time zones, it should be said that standard time of the III time zone has been introduced in Moscow. Indeed, noon in the Moscow region comes at 12:19 (in the east) and at 12:39 (on the western border). By the time of noon, it is easy to understand that the eastern part of the region, stretching along the longitude of 11 minutes, falls into the III zone, and the western (9 minutes of longitude) - into the II time zone.
On the territory of our country until 28.03.2010 there were 11 time zones from II to XII, therefore, the New Year on the territory of Russia could be celebrated 11 times (from 15.00 Moscow time to 1 am). Now in our country there are 9 time zones: from II to XI, excluding IV. Now the New Year in our country will be celebrated only 9 times: at 16.00 Moscow time, then at 18.00, 19.00 and so on until 1 am. In the second zone - only the Kaliningrad region, in III - Moscow, Voronezh, Kazan, Izhevsk, Samara and many other cities, and in XI - Chukotka Autonomous Region, Kamchatka Territory and Magadan Region. Thus, the time difference between Anadyr and Kaliningrad is 9 hours.
Our country "stretched" in longitude by 171 degrees. If this number is divided by 15 (the width of the time zone), then we get the number 11.5. This means that Russia should have 11 or 12 time zones. Look at the globe: the meridians converge at the poles, which means that the time zone becomes wide when moving south, and narrow when moving north.
In the northern territories, you can drive 600-800 km in the west or east directions, and we will find ourselves in a different time zone, and at the equator we need to move about 1500 km.
Problem solving algorithm
according to standard and local time.
Definition of standard time
Task: Determine the standard time of Magadan, if it is 6 hours in Moscow.
Actions:
1. Determine what time zone the points are in
Moscow 2; Magadan 10;
2 .Determine the time difference between items
10 -2 =8 (difference between points in time)
3. Calculate standard time (determine which point is to the east, which is to the west.) Magadan is to the east, which means there is more time there, therefore, the time difference must be added to Moscow time. 6 +8 = 14 hours
Answer: Standard time of Magadan is 14 hours.
Determination of local time
Task: Determine the local time in Magadan if it is 6 hours in Moscow.
Actions:
1. Determine the geographical longitude of the points
Moscow 37°E; Magadan 151°E;
2. Calculate the difference in degrees between points
151°-37°=114°
3. Calculate the time difference between points
114 x 4 \u003d 456:60 \u003d 7.6 hours (this is 7 hours 36 minutes, because 0.6 hours x 60 minutes = 36 minutes)
4. Determine the local time (add the time of Moscow and the time difference.)
6 + 7 hours 36 minutes = 13 hours 36 minutes
Answer: Local time in Magadan is 13 hours 36 minutes
Notes :
0.1 hour - 6 minutes
0.2 hours -12 minutes
0.3 hours -18 minutes i.t.d
Tasks for determining standard time
The plane took off from Chita (8th time zone) to Murmansk (2nd time zone) at 22:00.
The plane landed in Murmansk at 21:00. How long was the plane in flight?
Solution:
To answer the task, you need to determine the time difference in two cities. It is known that the time of each time zone differs by 1 hour. For Chita and Murmansk, the difference is
(8 - 2 = 6) 6 hours Knowing that Chita is located east of Murmansk, we conclude that in Chita
time is 6 hours more than in Murmansk. So the plane took off from Chita when it was (22 - 6 = 16) 16 hours in Murmansk, and landed in Murmansk at 21 hours. Accordingly, it was in flight for 5 hours.
Tasks:
1. The plane took off from Chita (8th time zone) to Murmansk (2nd time zone) at 15:00 local time. The flight time from Chita to Murmansk is 5 hours. What time will it be in Murmansk when the plane lands? Answer: 14 hours
2. Determine when Moscow time will land in Moscow (2nd time zone)
an airplane that took off from Yekaterinburg (4th time zone) at 11 am local time and was in flight for 2 hours. Answer: 11 am.
3. Determine when Moscow time will land in Moscow (2nd time zone)
An airplane that took off from Novosibirsk (5th time zone) at 11:00 local time and was in flight for 5:00. Answer: 13:00.
4. The plane took off at 9 am from Moscow (2nd time zone) to Yakutsk (8th time zone).
When, according to local time, will the plane land in Yakutsk, which was in flight for 5 hours?
Answer: 20 hours
5. What time (including maternity leave) will it be in Krasnoyarsk (6th time zone) if it is midnight in London? Answer: 7 hours.
6. What time (including maternity leave) will it be in Murmansk (2nd time zone) when it is 12 noon in London? Answer: 3 p.m.
7. Determine the standard time (including maternity time) of Krasnoyarsk (6th time zone), if it is 11 a.m. in London. Answer: 18 p.m.
8. What time is it in Omsk (5th time zone), when is 3 pm in Moscow? Answer: 18 hours
9. What time, taking into account maternity leave, will it be in Vladivostok (9th time zone) when it is midnight in London? Answer: 10 o'clock
To solve problems for determining standard time, it is necessary: to carefully study the map of time zones in Russia and the world. Pay attention to the time difference on the territory of Russia and the world, have a clear idea of standard, maternity, Moscow time; remember the location of the international date line.
The main theses of the topic: time zones of the world.
In each time zone, time is calculated according to the meridian passing through its middle. This time is called zone time. It differs from the time of the neighboring zone by exactly one hour. The belts are counted from west to east. The zero zone is taken as the belt along the axis of which the Greenwich meridian passes.
Local time is the time on one meridian at each point.
The territory of Russia is located within 11 time zones, from 2 Moscow to 12. Eleven hours separate the Kaliningrad region from Chukotka in the east.
Date line. In order to avoid confusion with the days of the year, an international agreement has established a date line. It was carried out according to geographical maps approximately along the 180th meridian, bypassing the land. If we cross this line from west to east, then we will make a T + 1 turn, i.e. T + 1 day, and, oddly enough, we will arrive yesterday. Therefore, crossing this line from west to east, we must count the same day twice. When crossing the international date line from east to west, on the contrary, skip one day.
Decree time. By a special resolution (decree) of the Council of People's Commissars in 1930, standard time in the country was moved one hour ahead. This was done for a more efficient, full use of daylight hours.
Summer time. Day length increases in summer. On the last Sunday of March across the country, daylight saving time is introduced: the clocks are moved back one hour. In autumn, on the last Sunday in October, daylight saving time is cancelled.
Tasks for determining standard time .
1. Determine the summer time in Yakutsk, in Magadan, if it is 10 am in Moscow?
2. Determine the time in Brazil, if it is 8 hours in Moscow?
3. What system would be used to measure time on the Earth if it did not rotate around its axis?
4. The ship, which sailed from Vladivostok on Saturday, May 24, arrived in San Francisco (USA) exactly 15 days later. What date, month, and day of the week did he arrive in San Francisco?
5. It's noon on the zero meridian, and 17-00 on the ship. What ocean is the ship sailing in?
6. If it's 12:00 in London, what time is it in Moscow and Vladivostok time zone?
7. What time is it in Magadan local time, if on the Greenwich meridian line
12-00?
8. A resident of Alaska flew to Chukotka. How many hours does he need to move the hands?
9. How many times can you celebrate the New Year in our country?
Solving problems in local and standard time.
Task №1.
At 30°E Wednesday, January 1, 18:00 local time. What is the day of the week, date and time on the 180th meridian?
Solution:
1.Find the difference in degrees and in time between 30°E. and 180 degree meridian:
180°- 30°E = 150°: 15°/hour = 10 hours (this is the time difference).
Since the 180 meridian is located east of 30 ° E, then by local time 30 ° E. (18 hours) you need to add the time difference i.e. 10 hours:
18 hours + 10 hours = 28 hours (1 day and 4 hours).
Answer:
Task number 2.
Standard time in Kyiv is 12 noon. At point A, the local time is 9:00, and at point B, it is 14:00.
Determine the geographical longitude of points A and B.
Solution:
Longitude of Kyiv - 31 ° E
For point "A"
1) 12 hours - 9 hours = 3 hours;
2) 3 hours×15° = 45°;
3)45° - 31° = 14°W.
For point "B"
1) 14 hours - 12 hours = 2 hours;
2) 2 hours×15° = 30°;
3)31°+30° = 61°E
Answer:
The longitude of point A is 14°W, the longitude of point B is 61°E.
Task number 3.
On the 180th meridian - Monday, May 15, 15:00 local time. What date, day of the week and local time at: 45°E, 150°E, 0° longitude, 15°W, 170°W.
Solution:
a) 180° - 45° = 135: 15/hour = 9 hours
9 hours is the time difference between 180° meridian and 45° east. Since 45°E located east of 180° meridian, then
Answer:
b) 180° - 150° E = 30°, 30°: 15/hour = 2 hours,
15 hours - 2 hours = 13 hours.
Answer:
c) 180° - 0° = 180°, 180°: 15/hour = 12 hours
15 o'clock - 12 o'clock = 3 o'clock in the morning.
Answer:
d) 180° + 15°W. = 195°, 195°: 15/hour = 13
given the direction of the earth's rotation from west to east:
15:00 - 13:00 = 26:00 or 2:00 am, May 15, Monday.
Answer:
e) 180° – 170°W. = 10° × 4min= 40 minutes
15 hours + 40 minutes = 15 hours 40 minutes.
Answer:
Task number 4.
The plane took off from Pretoria (ΙΙ time zone) at 15 o'clock on December 1st and flew to the northeast. After 9 hours, he crossed the 180th meridian, and after another 2 hours he landed in Honolulu (14 time zone). What time and what date will it be in Honolulu at the time of landing.
Solution:
1. Determine the time difference between cities
24 - 14 - 2 = 12 hours
2. Determine the time in Honolulu at the time of landing from Pretoria. Since Honolulu is to the west,
15 – 12 = 3 hours
3. Standard time in Honolulu at the time of landing
3 + 9 + 2 = 14 hours.
Answer:
The height of the sun above the horizon.
Determination of geographical coordinates.
Task number 1.
Determine the geographical latitude of the city if it is known that on the days of the equinox the sun at noon is above the horizon at an altitude of 63 ° (the shadow falls to the south).
Solution:
The point is in the southern hemisphere. The height of the sun on the equinox days is determined by the formulah= 90° - φ. Determine the latitude of the point φ = 90° - 63° = 27°S.
Task number 2.
At what geographical latitude is city A located if the sun at noon on December 22 (the shadow falls to the south) is at an altitude of 70 ° above the horizon.
Solution:
It follows from the condition of the problem that point A is located in the southern hemisphere, since the shadow falls to the south. The height of the sun for the summer solstice (December 22 - summer in the southern hemisphere) is determined by the formulah= 90° - φ + 23° 30"
From this formula, you can find φ the latitude of the place i.e. city A
φ = 90° - 70° + 23°30" = 43°30"S
Answer:
The geographical latitude of the city A \u003d 43 ° 30 "S.
Task number 3.
Determine the geographical coordinates of the city - the capital, located to the west of Kyiv at 27 ° 30 ". The North Star in this place is visible at a distance of 54 ° from the zenith point.
Solution:
1. The longitude of Kyiv is 30 ° 30 "E. We can find the geographical longitude of the city
λ = 30°30" – 27°30" = 3°E
2. In the northern hemisphere, the geographical latitude of any point is equal to the angle between polar star and the horizon line. Finding latitude:
φ = 90° - 54° = 36°N
Answer:
Geographic coordinates 36°N. and 3°E
Task number 4.
In the city - the capital of the island state, the sun is highest above the horizon at 4 o'clock GMT during the day. During the year, the height of the sun varies from 52° to 90°. Name the city and state.
Solution:
1. Determine the time zone of the city:
12 o'clock – 4 o'clock = 8 time zone
2. Determine the geographical longitude knowing that every 15 ° time difference is 1 hour.
8 hours × 15° = 120° E
3. the city is located between the tropics, since the sun can be at its zenith (90 °)minthe angle of incidence of the sun's rays of 52 ° makes it possible to determine the geographical latitude during the winter solstice
φ = 90° - 52° - 23.5° = 14.5°
The city has geographical coordinates 14.5°N. and 120°E
Answer:
Manila, Philippines.
standard time a system of counting time based on the division of the earth's surface into 24 time zones: at all points within one zone at each moment of P. v. the same, in neighboring zones it differs by exactly one hour. In the standard time system, 24 meridians, 15 ° apart in longitude, are taken as the average meridians of time zones. The boundaries of belts on the seas and oceans, as well as in sparsely populated areas, are drawn along meridians that are 7.5° east and west from the mean. In other regions of the Earth, for greater convenience, borders are drawn along state and administrative borders close to these meridians, railways, rivers, mountain ranges, etc. (cm. time zone map
). By international agreement, the meridian with a longitude of 0 ° (Greenwich) was taken as the initial one. The corresponding time zone is considered to be zero; This zone is called universal time. The remaining belts in the direction from zero to the east are assigned numbers from 1 to 23. The difference between the P. in. in any time zone and universal time is equal to the zone number. The time of some time zones has received special names. So, for example, the time of the zero zone is called Western European, the time of the 1st zone is called Central European, the time of the 2nd zone is foreign countries called Eastern European Time. Time zones from the 2nd to the 12th inclusive pass through the territory of the USSR. In order to make the best use of natural light and save energy, in many countries during the summer time clocks are moved forward by one hour or more (so-called summer time). In the USSR, Decree time was introduced in 1930; The clock hands have been moved forward an hour. As a result, all points within this zone began to use the time of the neighboring zone, located to the east of it. Decree time of the 2nd time zone in which Moscow is located is called Moscow time. In a number of states, despite the convenience of standard time, they do not use the time of the corresponding time zone, but use throughout the territory either the local time of the capital, or a time close to the capital. In the astronomical yearbook Nautical almanac (Great Britain) for 1941 and subsequent years, descriptions of the boundaries of time zones and the accepted account of time are given for those places where P. in. is not used, as well as all subsequent changes. Before P.'s introduction of century. widespread in most countries civil time, which is different at any two points whose longitudes are not the same. The inconveniences associated with such a counting system became especially acute with the development of railways. messages and means of telegraph communication. In the 19th century in a number of countries they began to introduce a single time for a given country, most often the civil time of the capital. However, this measure was unsuitable for states with a large length of territory in longitude, because the accepted account of time on the distant outskirts would differ significantly from the civil one. In some countries, common time was introduced only for use in railways and telegraph. In Russia, the civil time of the Pulkovo Observatory, called St. Petersburg time, served for this purpose. P. in. was proposed by the Canadian engineer S. Fleming in 1878. It was first introduced in the United States in 1883. In 1884, at a conference of 26 states in Washington, an international agreement on timekeeping was adopted, but the transition to this system of time counting dragged on for many years. On the territory of the USSR, P. century. introduced after the Great October Socialist Revolution, from July 1, 1919.
Big soviet encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .
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