Winter and summer time. From winter to summer: Where and when the clocks are changed Define summer time

On July 14 (July 1, old style), 1917, the transition from “winter” to “summer” time was carried out in Russia for the first time.

The expression “summer time” or “Daylight Saving Time” means shifting one hour ahead of the time in a given time zone. Entered on summer period in order to save electricity by the governments of a number of countries approximately north of 30° north latitude and south of 30° south latitude.

Changing the clock hands to “summer” time is not advisable everywhere. At tropical latitudes (less than 23.5°), the length of daylight hours varies little throughout the year. At polar latitudes (more than 66.33°) there is a polar day and a polar night. The effect of changing the clock hands to “summer” and “winter” time can occur in the latitude range from 30 to 55°.

Dates of summer time in different countries decreasing from north to south, amounting to 20-30 weeks in April-May, summer months and September-October (in the northern hemisphere) and about 20 weeks in November-March (in the southern hemisphere). With a significant decrease in daylight hours, the time is set back an hour. The mode of life according to standard standard time is commonly called “winter” time.

The idea of ​​changing clocks first arose in the 18th century from the American public figure Benjamin Franklin in order to save candles for lighting, but was blocked by candle manufacturers.

In 1895, New Zealand entomologist George Vernon Hudson submitted a paper to the Wellington Philosophical Society in which he proposed a two-hour shift to preserve daylight.

The idea of ​​​​introducing "summer" time found support in most economic developed countries at the beginning of the 20th century, during the period of mass electrification of industry and everyday life. More rational use daylight hours was supposed to reduce energy costs for indoor lighting.

In Great Britain, in 1909, a bill was drawn up to introduce “summer” time, which was repeatedly considered in Parliament, but was never adopted before the First World War.

Many states abandoned "summer" time immediately after the end of the war, others repeatedly introduced this time, then abandoned it, and some countries maintained this time shift throughout the year.

The transfer to “summer” time was introduced when crisis situations arose, for example, during the Second World War (USA, UK), during the oil crisis of 1973-1974 (USA, Germany and other countries).

In Russia, this transition was first carried out on July 1 (July 14, new style) 1917, when, in accordance with the decree of the Provisional Government, the hands of all clocks in the country were moved forward one hour.

They were transferred back on December 27, 1917 (January 9, 1918 according to the new style) in accordance with the decree of the Council of People's Commissars of December 22, 1917 (January 4, 1918 according to the new style).

The practice of changing from "summer" to "winter" time continued until 1924.

Council resolution people's commissars USSR, on June 16, 1930, maternity time was introduced on the territory of the USSR. Then the clock hands were moved one hour ahead relative to standard time and after that they were not moved back, and the country began to live and work all year round, one hour ahead of the natural daily cycle. The transfer of clock hands to “summer” time was resumed on April 1, 1981, but this time relative to maternity time. Thus, in the country, “summer” time was ahead standard time for two hours.

In the USSR, and since 1991 in Russia, the introduction of “summer” time was carried out on the night of the last Saturday on the last Sunday of March, and “winter” time - on the night of the last Saturday on the last Sunday of September.

In 1996, the period of “summer” time in Russia was “in order to maintain a single time regime with other countries. The transition to “winter” time began to take place on the last Sunday of October, as in all of Europe.

At the same time, the majority of the Russian population opposed daylight saving time.

On July 21, 2014, Russian President Vladimir Putin spoke about Russia’s transition to “winter” time from October 26, 2014. In most regions of the Russian Federation, the clocks were set back an hour, and in the future the seasonal change of hands was not carried out. Five regions of Russia (Udmurtia, Samara region, Kemerovo region, Kamchatka Territory and Chukotka autonomous region) have not switched to "winter" time.

After this, complaints began to be received from a number of regions about the lack of sunlight in the evenings. In 2016 Russian authorities approved laws that made it possible to move the clock hands forward: in the Altai Republic, Altai and Trans-Baikal Territories, Sakhalin, Astrakhan, Magadan, Tomsk, Ulyanovsk, Novosibirsk and.

Currently, there is a consensus among experts and the international community about significant savings in energy resources during the transition to summer time No.

In 2017, more than 70 countries and territories switched to summer/winter time. From the former Soviet republics Only Moldova, Ukraine and the three Baltic republics - Latvia, Lithuania and Estonia - introduced daylight saving time.

The material was prepared based on information from RIA Novosti and open sources

On March 27, 2011 in Russia I was in last time Daylight saving time has been switched over. There will be no more seasonal shifts in the officially accepted time; Russians will begin to live with a constant shift of +2 hours relative to standard time. The 2-hour shift is caused by the fact that in Russia there is so-called “maternity time”, which differs from standard time by +1 hour. Daylight saving time adds another +1 hour to maternity time, for a total of +2 hours relative to standard time.

what is winter and summer time

Daylight saving time is time shifted one hour ahead of the usual time in a given time zone. Similar to daylight saving time, standard time is also called winter time.

Why are winter and summer time introduced?

Summer time is introduced in many countries in the summer in order to save electricity for lighting. However, there is an opinion that the effectiveness of such a measure is insignificant, while the harm caused to human health caused by the forced displacement of natural biological cycles is great.

when winter and summer time were first introduced

Daylight saving time was first introduced in Great Britain in 1908. In Russia, the transition to summer time was first implemented in July 1917 and was in effect until 1930, when the clock hands were moved one hour ahead relative to standard time. This time was called “maternity leave”, as it was introduced by the Decree of the Council of People’s Commissars on June 16, 1930. Since 1981, summer time has been regularly introduced again in the USSR.

Which countries use winter and summer time?

Currently, in the northern hemisphere, summer time is used in the USA, Canada, European countries, and throughout Russia. In the southern hemisphere, summer time is used in Australia, New Zealand, Paraguay, Brazil, and Chile. Countries near the equator do not use summer time.

When does the transition between winter and summer time occur?

In Russia and Europe, the transition to summer time is carried out on the night of the last Sunday in March at 2:00 by moving the clock hands 1 hour forward, and the reverse transition is carried out on the night of the last Sunday in October at 3:00 by moving the hands back 1 hour.

In the USA and Canada, since 2007, daylight saving time begins on the second Sunday in March at 2:00, and returns on the last Sunday in October, also at 2:00.

offset of winter and summer time relative to zone time

Due to the use of summer time in Russia, Russians live with a shift of +2 hours relative to standard time. The 2-hour shift is caused by the fact that in Russia there is so-called “maternity time”, which differs from standard time by +1 hour. Daylight saving time adds another +1 hour to maternity time, for a total of +2 hours relative to standard time.

1. Local time.

Time measured on a given geographic meridian is called local time this meridian. For all places on the same meridian, the hour angle of the vernal equinox (or the Sun, or the mean sun) is at any moment the same. Therefore, throughout the entire geographic meridian, local time (sidereal or solar) is the same at the same moment.

If the difference geographical longitudes there are two places D l, then in a more eastern location the hour angle of any luminary will be at D l greater than the hour angle of the same star in a more western location. Therefore, the difference in any local times on two meridians at the same physical moment is always equal to the difference in the longitudes of these meridians, expressed in hourly measure (in time units):

those. the local mean time of any point on Earth is always equal to universal time at that moment plus the longitude of that point, expressed in hourly units and considered positive east of Greenwich.

In astronomical calendars, the moments of most phenomena are indicated in universal time. T 0 . Moments of these phenomena in local time T t. are easily determined by formula (1.28).

3. Standard time. IN everyday life Using both local mean solar time and universal time is inconvenient. The first is because there are, in principle, as many local time systems as there are geographical meridians, i.e. countless. Therefore, in order to establish the sequence of events or phenomena noted in local time, it is absolutely necessary to know, in addition to the moments, also the difference in longitude of those meridians on which these events or phenomena took place.

The sequence of events marked by universal time is easy to establish, but the large difference between universal time and the local time of meridians located at considerable distances from Greenwich creates inconvenience when using universal time in everyday life.

In 1884 it was proposed belt average time counting system, the essence of which is as follows. Time is counted only by 24 main geographical meridians located from each other in longitude exactly 15° (or 1 h), approximately in the middle of each time zone. Time zones are the areas of the earth's surface into which it is conventionally divided by lines running from its north pole to the south and spaced approximately 7°.5 from the main meridians. These lines, or boundaries of time zones, accurately follow geographic meridians only in open seas and oceans and in uninhabited land areas. For the rest of their length they follow government, administrative and economic or geographical boundaries, retreating from the corresponding meridian in one direction or another. Time zones are numbered from 0 to 23. Greenwich is taken as the main meridian of the zero zone. The prime meridian of the first time zone is located from Greenwich exactly 15° east, the second - 30°, the third - 45°, etc. until the 23rd time zone, the main meridian of which has an east longitude from Greenwich of 345° (or west longitude 15°).

Standard timeT p is the local mean solar time measured at the prime meridian of a given time zone. It is used to keep track of time throughout the entire territory lying in a given time zone.

Standard time of this zone n connected with universal time by an obvious relationship

It is also quite obvious that the difference in the zone times of two points is an integer number of hours equal to the difference in the numbers of their time zones.

4. Summer time. In order to more rationally distribute electricity used for lighting enterprises and residential premises, and to make the fullest use of daylight in the summer months of the year, in many countries (including our republic), the clock hands of clocks running in standard time are moved forward by 1 an hour or half an hour. The so-called summer time. In the fall, the clocks are again set to standard time.

Daylight saving time connection T l any point with its standard time T p and with universal time T 0 is given by the following relations:

When traveling around the world, people inevitably find themselves in different times days - 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 throughout its entire length from Northern to 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. Capital Russian Federation- Moscow is 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 Russian territory, all work of river, sea, aviation and railway transport, as well as various types of communications are 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.

Independently calculate the standard time of each individual settlement It's not difficult at all. 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 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.

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