The meaning of the action is voluntarily refusing to consume electrical energy for one hour. Thus, society is aware of the importance of taking measures to reduce the negative impact of human activity on the environment.

For the first time this great idea was implemented in Sydney, Australia in 2007. Then about two million residents of the metropolis took part in the action, and energy savings amounted to about 10%.

Inspired by the example, every year more and more new cities began to join the action "Earth Hour". It is expected that in 2020, residents of more than 7 thousand settlements of our planet (more than 2 billion people) will take part in a voluntary power outage for 1 hour. Among the countries participating in the action, of course, there is Russia.

What date and time is Earth Hour 2020:

This year's Earth Hour is scheduled for Saturday. March 28, 2020. Promotion will start at 20:30 local time and will last for an hour, until 21:30.

That is, the action Earth Hour 2020 - what date is held and what time:
* Event date - March 28, 2020
* from 20:30 to 21:30 local time.

The shortest day of the year is December 21 or 22 (depending on the shift in the calendar). It has a special name - "Winter Solstice Day". This is the day of the shortest daylight hours (only 5 hours 53 minutes) and the longest night. From the next day, as you know, it begins to gradually increase. In scientific terms, this is due to the fact that the tilt of the Earth's axis of rotation relative to the Sun takes on a maximum value.

In many cultures, this day has always been a significant event, always associated with rebirth. For example, in primitive culture, the beginning of the Solstice was not exactly a joyful day, it was more associated with the onset of hunger. Because primitive people did not really know how much stock they needed to prepare for times of cold weather. In the Early Middle Ages, this was a holiday, as beer and wine were mostly matured by mid-December.

Longest day of the year

The longest day of the year occurs on June 21 or 20. You have probably already noticed that it is light outside even at 23:00. True, then, as with the “winter”, daylight hours begin to slowly decrease, this becomes noticeable already in August.

In the modern world, the days of the winter and summer solstices are not a holiday, but a lot of traditions have survived to this day. For example, carols beloved by children were originally dedicated on December 20, only then they migrated to the post-Christmas weeks until Epiphany (January 19). In ancient Egypt, the priests attached great importance to the summer solstice. In Russia, the holiday is better known as Ivan Kupala Day, when the celebrants bathe, jump over bonfires, guess and look for fern branches (which, according to legend, bloom on this particular holiday).

It is difficult to observe the solstice due to the fact that the sun is slowly moving towards its point. Only very recently have scientists begun to determine the exact time of an event down to the instant.

Solstice takes place twice a year - in summer and winter. The event got its name because of the location of the Sun in the sky - for several days Sun at noon is at one constant height or "standing", hence the solstice. Daylight hours on June 21, 2016 in Ulyanovsk will be 17 hours 12 minutes 48 seconds. Moreover, on June 20, daylight hours will be only two seconds shorter than on June 21, and on June 22 it will be reduced by four seconds.

The length of the day remains unchanged - 24 hours, but the duration of daylight and darkness changes throughout the year. Therefore, there is The shortest and longest daylight hours. The longest day of the year is called Summer Solstice. Accordingly, this day is the shortest night.

In everyday bustle, of course, we do not pay attention to the fact that already in winter the Sun rises higher and higher above the horizon. On June 21, the Sun is at its maximum height above the horizon.

In ancient civilizations on Earth, they worshiped the Sun, understood astronomy and followed its annual movement. They knew when the solstices and equinoxes came (the day is equal to the night), they celebrated these events as holidays. Oriented on them their lives and agricultural work.

Dear Ilya Petrovich!
Thank you for digressing against the backdrop of the intricate scientific discussions currently going on on our website to a comment on an issue that is not essential for humanity in my note: determining the exact moment of the onset of a phenomenon that is vague in time - reaching the maximum declination of the Sun on the day of the summer solstice.
Of course, you are right: according to my method, this is a search for an extremum, but not the height of the Sun above my horizon, as you wrote, but its delta (declination) coordinates on the celestial sphere (but measured from the moving point "My home").
Thank you very much for the tip about the "pole". (It's a shame that I didn't guess about it in time.) Yes, - in this case, "parallax arises", but in our case it "does not interfere", we do not measure the "delta" angle itself.
With the help of the same RedShifn-6, I "redefined" all the moments: the coincidence of the longitudes of the pole and the Sun (which are given in official sources and do not differ from mine) and the achievement of the maximum declination (which I was looking for only). And "measuring" them and from the north and from the south poles for days and summer and winter solstice in 2016 and 2014 years.
Here is what can be said as a result. Estimates from any pole are the same. But in summer 2016 year, the maximum declination of the Sun has come 2.5 minutes early than the earth and the sun are aligned by longitude. Not immediately, but I remembered that these days the Earth is approaching aphelion in its orbit, i.e. removed from the Sun and 2.5 minutes earlier was nearer to him. And since we measure its declination from the pole, and not from the equator, the parallax affects its value. But, without slipping into his calculation, I turned to the data on winter solstice: after all, there is the distance to the Sun decreases, and the declination grows (in absolute value), and its extremum should come later connections. But this logic didn't work. in winter the maximum declination will also be before connections ( 21.12. 2016 10:43 UTC) and even 5.5 minutes!
2014 th year confirmed these shifts, but with different numbers: summer - 21.06.2014 10:51 UTC, - 7.7 min; winter - 21.12.2014 23:02 UTC, - 2.0 min. Trying to find the reasons for such shifts, I recalled the displacements of the center of rotation of the Earth-Moon and Sun-planet systems, not believing that they were included in the disk calculation program RS-6 and their account will explain something. Maybe my method of determining the moment of extremum is wrong, as the middle of the time interval between the beginning and the end of the maximum value of the declination graph. What else, I don't know...

Good afternoon!

VI0540:

With the help of the same RedShifn-6, I "redefined" all the moments: the coincidence of the longitudes of the pole and the Sun (which are given in official sources and do not differ from mine) and the achievement of the maximum declination (which I was looking for only). And "measuring" them and from the north and from the south poles for days and summer and winter solstice in 2016 and 2014 years.

Did I understand correctly that you can indicate the longitude or meridian of the Earth, aligned with the Sun at the time of the Solstices? If this is so, then I will be grateful if you indicate these coordinates to me - exactly on the Earth

Dear Nadezhda Andreevna!
I omit explanations of a bunch of objective and subjective reasons for the delay in my response to your request. 10 days is too much. I'm sorry and I apologize. But - every cloud has a silver lining: the answer already prepared a few days ago, which caused me uncertainty, was mine calculation, less strict and accurate, and also contained a stupid typo. Having not easily figured out the various settings and modes of operation of the RS-6 disk, I used a primitive, but more reliable selection method. That is, for our cases, I was looking for a longitude on Earth, from which at the moments of solstices and equinoxes the Sun was observed at the zenith. And all the calculations were done by RS-6 (i.e., I put all the "responsibility" on him). But now everything is clear, and I have no doubts about the results.

Time and coordinates of the Sun at the zenith:

Summer solstice 20.06 .2016 22 hour 33.7 min UTC. Latitude: + 23.43°, longitude: -158.53°(zap)
Winter solstice 21.12 .2016 10 h 43.8 m in UTC. Latitude: - 23.43°, longitude: + 018.62°(east)

spring equinox 20.03 .2016 04 hour 33.2 +113.57°(east)
autumnal equinox 22.09. 2016 14 hour 20.4 min UTC. Latitude 00.00°, longitude - 036.99°(zap.)

To evaluate d authenticity From these results I will say that in the table of astronomical events of the disk R ed S ift- 6 the moments of the beginning of the "seasons of the year 2016" exactly on 1 minute outu less similar data from Wikipedia. (But this is - "mind me"! I just detailed them to the utmost with subsequent rounding). I remind you that for 1 minute utu the longitude of the Sun changes by 0.25°.

P.S. Your Question and Answer About the Moon's Orbit Ingus I'm also interested, but I still need to figure it out.
(Yes... About 40 years ago, for some reason, I felt more confident in matters of spherical astronomy. What is it?..)

Dear VI0540!

You have no idea what a service you have done for me. I thank you with all my soul and pure heart.

One more clarification - Do these coordinates change over the years?

And I am sincerely glad that it turned out what you need!
You're asking : "Do these coordinates change over the years?"
It is known that many astronomical phenomena are repeated year after year. Except for some, of course. For example : weather, position of the planets, days of the week, Easter day ... It is also known that our year is not simple, calendar, but - tropical, equal to 365 days with an almost six-hour tail. And people are impatient people, "and they are in a hurry to live and feel in a hurry." Do not wait another quarter of a day before the New Year's table until the current year ends! Here we are discarding this "tail" and starting the next calendar year ahead of schedule. And our "solar meridians" will have to turn these ~ 350 minutes until the moment of "ripening" of the necessary conditions for the opening of the next season (spring - summer -...) From their last year's places they will have to move to the west by (~ 350 * 0.25 °). And after 4 years, we will introduce a leap day ... So it turns out that if you need to have data for a different period, then it is easier to calculate them again than to determine the shifts of the previous ones, being afraid to get confused when the eastern longitude decreases, goes into the western, which, on the contrary, increases ... Order immediately a new calculation, which you need. (Application - in writing through the LCI website.)

Nadezhda, excuse me for this long comic "educational program". The shortest answer is in the comment headings. And - success and good luck to you in everything! (Not only in the definition and use of "solar meridians".)

Good afternoon, VI0540!

That's why I asked - does the meridian itself change over the years. After all, these are the key points of the Earth system. And accuracy matters. Very important. The fact that the year is artificially calculated confuses all the cards.

How to get to your site? The search found either --site of lies----, or ---site does not work.

Good evening, Nadezhda Leshchenko!
Determining the positions of the meridians for you, I did not delve into what task it is necessary to solve. And now it is not clear to me what "key points ..." we are talking about, what an "artificially calculated year" is, and why it "confuses all the cards." But I think there is no need to waste time on these explanations now. Let's find out what you need.

"Accuracy matters."So, and original value accuracy- the time of the onset, relatively speaking, of spring, summer ... what we did above, or another phenomenon you need - it doesn’t matter. To what extent: minutes, seconds? AND - result accuracy- the angle of longitude, the meridian of the Sun on Earth, - up to degree, minute of arc or second? You will set this yourself.

"How to get to your site?"This is apparently a question on my joke offer" Application in writing..."But we are with you now chatting on the LCI website. I just meant it. Although, if you need to discuss some private issue that is not of interest to everyone, you can use e-mail. This and emerging questions on this topic. Or, for example, to your recent question about the orbit of the Moon, there is a drawing attached with some inaccuracies and even errors that make it difficult to understand (at least to me). They can be unhurriedly clarified by e-mail, without taking up precious space on our website.
Here is my mailbox address: . I think anyone can write to me.

Thank you. I read it - and it became funny about the site itself.

But for the mail - I thank you separately. I seem to be somewhat confusing trying to explain my idea. Or we speak a little different languages ​​- we need to somehow work out common terms, apparently. I'd rather email you. Thanks again.

Unfortunately, the mailers answer me--- Address SH-V-I-40 yandex en. in the To field not recognized. Check that all addresses are entered correctly.

You failed to write

I have been using a computer for a long time, but I don’t understand a lot and I still feel like a “teapot”. I also discovered that in my text, already recorded on the site, "someone" underlined my email address, and now, by clicking on it, we are offered to make some kind of adjustment (!?) (Or maybe it's a glitch in my computer !.. Isn’t it the same for others?)
By mail, we communicated with Sol, Polina; they reported their addresses, it seems, by telephone. There are no typos in my address. Here is another copy of the address, taken from the open page of my mail: SH-V-I-40 yandex en.
I thought if you write your address like me at first, here, and I will send a message to him from my mail, then what is it ... - will it also not work? What shall we try? Or shall we turn to specialists?

(Now our colleagues on the site are reading - how two "teapots" are trying to chat over a cup of tea - and laughing. You, Nadezhda, forgive me for dragging you into this "humor". Let the people relax. You, it seems to me , don't be afraid of that. From us, I think, it will not decrease .... In the meantime, we will solve the "problem" silently, if someone does not delicately tell at the ill-fated address - what's the matter.)

Good evening!

I don't mind laughing a little. What to do - "teapot" is "teapot", I am also like that. Let them smile.

My mail factortor gmail com.

I already somehow, I don’t remember with whom, it was like that. This is not a computer. It's something else.

Tried again - same thing.

The Egyptians honored the goddess Sopdet. The heliactic rising of her star foreshadowed the flooding of the Nile, an event of the greatest agricultural significance. And they had three seasons, not four, like ours. And the equinox did not seem to bother them much: the length of the day in those latitudes does not change so radically throughout the year as in St. Petersburg, for example.

It would be interesting to expand the heliactic risings of Sirius into the past, taking into account the precession. in terms of dating. Spin the rings, so to speak. Combine the solstice, the heliactic rising of Sirius and the flood of the Nile. How did it all fit in the timeline of the past?

Ingus writes:

It follows that no reliability in predicting the floods of the Nile by stargazing could be obtained. From this we can conclude that observations of the stars served a completely different task. Which - I do not know, but not the floods of the Nile. It's just useless.

However, the release of energy (water) into the Nile system is a stable phenomenon over time (see the hydrograph of the Nile for 20 years.) The rise in level begins shortly after the summer solstice. Monsoons from the Indian Ocean condense in the coolness of the Ethiopian highlands and fill the Blue Nile. And he brings all this abundance to Bely. The maximum lift level varies from year to year, but the time frame does not. The spectacular pre-dawn appearance of Sirius in the Egyptian sky after a long absence preceded the flood of the Nile for quite a long period of Egyptian history. As I understand it, now the heliactic rising of Sirius falls almost at the very peak of the water ..

I agree. Astronomers cannot accurately predict the weather, and neither can meteorologists.

Interestingly, astrologers predict the weather? :) I'll go and study the issue.

Ingus writes:

It's all about "shortly after...". The arrival of spring or summer does not require astronomical observations. This is so visible. Naturally, the annual temperature cycle is visible on the graphs, but it is immersed in a chaotic component with a sufficiently large dispersion, which does not allow weather changes to be predicted with useful accuracy. The same goes for the monsoon period. The arrival of monsoons can vary within fairly wide limits and this has nothing to do with astronomy. Determining the date when the Sun rises approximately in the east does not require the construction of complex structures, especially since the Nile floods only "shortly after" this.

Don't worry too much - astrologers can't predict the weather. Rather, it can be predicted by signs. For example, boiling water in a kettle - not so noticeable in a saucepan - makes a different noise in different weather. Accuracy - from a day to 3-4 hours.

If the birds bathe intensely in puddles or dust, this is to rain or snow. - the same, from days to several hours

If the moon even through the clouds seems clear and bright - wait for good weather. If, even in cloudless weather, as if in a haze - wait for the weather to worsen

For a long time I could not think of anything to say about this phenomenon. In theory no "standing" there is no difference between a gradual increase in declination and altitude of the Sun and their subsequent decrease. And separates them moment, the instant when a plane drawn through the Earth's axis of rotation normal to the plane of the orbit and moving along it at a speed of 30 km/sec crosses the direction by center Sun. How to define this moment that changes our joyful expectation : "summer is yet to come", - sadly : "and the day is already waning"? I did not immediately realize that the direction of the plane through the axis is 90 ° away from the vernal equinox. Therefore, I went the long way : definition moment of reaching the maximum solar declination (about +23°26" this year).

There are some interesting numbers here. The RedShift-6 calculation disk that I used determines the declination with an accuracy of 0.01 "(arc second). On Earth, the latitude of the subsolar point with such a meager change in the declination of the Sun increases by only about 3 m. Here is how the upper section looks approximately" solstice", the last 3-meter movement of the sun point on the earth's surface (graph not to scale).


And - the result. With an error of 0.01 "(arcsecond) specified by the program, the moment of reaching the upper point of the solar declination graph is determined using this method not more accurately than a whole minute and is equal to June 21, 2016 08:04 Moscow time. But, since the concept of "MSK" has recently been arbitrary and unscientific, and scientists are either silent, or the authorities prefer to make "democratic" decisions, taking into account the illiterate the majority it is more reliable to express the time in Greenwich Mean Time : 05 h 04 min MT(world time). (I myself am already confused in this leapfrog over time.) This is it middle"standing".
When calculating, it turned out that if we consider the decrease in the height of the Sun by half its diameter, which practically imperceptibly and changes the length of the day and night by only 5 minutes, then it takes more than a week. Here's to you standing for half a month!

And what do we see on the Internet on this topic? Everyone celebrates start of the longest day, marking the first half of the "solstice", since neither its beginning nor its end are defined. Moreover, in the Russian media (I didn’t come across others) it is given everywhere Moscow midnight, apparently considering this particular Moscow day the longest in the northern hemisphere.
I would mark the conditional beginning (end) of the "solstice" days 7-8 days from the middle, and June 21-22 - the time of "the middle of the longest (short - for the southern hemisphere) day on Earth this year." But we have already weaned ourselves from precise definitions and understanding of the essence of phenomena...

PS. I have looked at the article Sol 14:51 Moscow time. What is this moment? ~12:16 Moscow time(summer, "maternity").

VI0540 writes:

I have looked at the article Sol dated 06/20/14. Sorry, Ilya, I have no comment, but I will only ask a question about the time you have given: 14:51 Moscow time. What is this moment? I have the moment of maximum declination of the Sun on this day ~12:16 Moscow time(summer, "maternity").

Dear Vsevolod Ivanovich, according to the summer solstice in 2014 came 21st of June in 10:51 UTC. We add 3 hours to UTC according to the time zone of Moscow and one more hour of the then daylight saving time, we get 14:51 Msk.

And for 2016 the time of the summer solstice is also indicated there: June 20 22:34 UTC, which corresponds June 21 01:34 Moscow time. This also does not match your data. 05:04 UTC.

Moreover, if in 2014 the discrepancy turned out +2 h 35 m, then in 2016: -6 h 30 m(!). The reason is still unclear to me.

Thanks Sol for his remarks about the discrepancy between my data and the data in his link. Indeed, the definition of the moment of "solstice" by the coincidence of the longitude of the polar axis of the Earth (along the ecliptic) and the Sun, which I was too lazy to do right away (more precisely, I did not immediately understand how) - gives the correct result 01:43 Moscow time. And it doesn't matter - to take the North Pole, directed from the Sun, or the South, which is from it. And I wanted to define it not indirectly(after all, the coincidence of "horizontal" coordinates is only a condition under which the "vertical" coordinate we are looking for - the declination of the Sun - is maximum), but straight directly measuring the increasing declination.
The error in these measurements was as follows. Fairly considering that the coordinate of the "sunsolar" point on the Earth, now turned by its northern hemisphere to the Sun, depends only on its position in space, I did not take into account all initial settings astro-disk program RedShift-6, which was used for the calculation. The solar declination was determined from a specific point on earth, and the default is My Home. It turns out that when choosing the moment of the extremum of this declination, "my house", as the starting point of measurement, itself shifted along another non-linear trajectory (rotation around the earth's axis). The result is involuntary distorted. It would be possible with step-by-step selection to "move" to the sunflower point each time, but in the manual version it is cumbersome. It's best to be in center of the earth: it is he who is always in the same plane (ecliptic) with the center of the Sun (more precisely, the solar system, I don’t know the difference, but this is clearly more accurate). But it turned out that RedShift-6, designed for a normal observer, for some reason does not provide for looking at the stars from the center of the Earth.
Confused me and media reports that "solstice 2016 falls at 1h 34 min Moscow time". I know that this is exactly how much (more precisely 1 hour 30 minutes) the clock is showing now ("summer + daylight savings" time), when specifically in Moscow the deepest midnight comes (averaged over the year). So I thought that the media take midnight of the city of Moscow as the moment of the onset of the "global" event, which has nothing to do with this.
It is a pity that the media does not use another Russian name for this day" solstice". It more correctly marks the moment of the end of the rise in the height of the Sun and the beginning of its decline. I already wrote that the content of the phenomenon and the term " solstice"It also needs to be sorted out...

The solstice is one of the two days of the year when the height of the sun above the horizon at noon is at its minimum or maximum. There are two solstices in a year - winter and summer.

On the winter solstice, the sun rises to its lowest point on the horizon.

In the northern hemisphere, the winter solstice occurs on December 21 or 22, which is when the shortest day and longest night occur. The moment of the solstice shifts every year, since the duration of the solar year does not coincide with calendar time.

In 2016, the winter solstice begins on December 21st. The sun, moving along the ecliptic, at this moment will reach the most distant position from the celestial equator towards the South Pole of the world. Astronomical winter will come in the Northern Hemisphere of the planet, and summer will come in the Southern Hemisphere.

On this day, at the latitude of Moscow, the Sun rises above the horizon to a height of less than 11 degrees.

In these December days, beyond the Arctic Circle (66.5 degrees north latitude), the polar night sets in, which does not necessarily mean complete darkness throughout the day. Its main feature is that the Sun does not rise above the horizon.

At the North Pole of the Earth, not only the Sun is not visible, but also twilight, and the location of the luminary can only be recognized by the constellations. A completely different picture in the region of the South Pole of the Earth - in Antarctica at this time the day lasts around the clock.

On December 21, the Sun crosses the 18 hour meridian and begins to rise up the ecliptic, beginning its journey to the vernal equinox when it crosses the celestial equator.

For thousands of years, the winter solstice has been of great importance for all the peoples of our planet, who lived in harmony with natural cycles and organized their lives in accordance with them. Since ancient times, people have revered the Sun, realizing that their life on earth depends on its light and heat. For them, the winter solstice represented the victory of light over darkness.

So, in Russian folklore, a proverb is dedicated to this day: the sun - for the summer, winter - for the frost. Now the day will gradually increase, and the night will decrease. The winter solstice was used to judge the future harvest. In the old days, on this day they noticed: frost on the trees - to a rich harvest of grain.

In the 16th century in Russia, an interesting ritual was associated with the winter solstice. The bell warden of the Moscow cathedral, who was responsible for the chiming of the clock, came to bow to the tsar. He reported that from now on the sun turned to summer, the day is added, and the night is reduced. For this good news, the king rewarded the headman with money.

The ancient Slavs celebrated the pagan New Year on the day of the winter solstice, it was associated with the deity Kolyada. The main attribute of the festival was a bonfire, depicting and invoking the light of the sun, which, after the longest night of the year, had to rise higher and higher. The ritual New Year's cake - a loaf - also resembled the sun in shape.

In Europe, these days began a 12-day cycle of pagan festivities dedicated to the winter solstice, which marked the beginning of a new life and the renewal of nature.

On the day of the winter solstice in Scotland it was customary to launch the sun wheel - the "solstice". The barrel was smeared with burning tar and let down the street. The wheel is a symbol of the sun, the spokes of the wheel resembled rays, the rotation of the spokes during movement made the wheel alive and looked like a luminary.

The winter solstice was determined before all other seasons in China (there are 24 seasons in the Chinese calendar). In ancient China, it was believed that from this time on, the male force of nature rises and a new cycle begins. The winter solstice was considered a happy day worthy of celebration. On this day, everyone - from the emperor to the commoner - went on vacation. The army was brought into a state of waiting for orders, border fortresses and trading shops were closed, people went to visit each other, gave gifts. The Chinese made sacrifices to the god of Heaven and ancestors, and also ate porridge made from beans and sticky rice to protect themselves from evil spirits and diseases. Until now, the winter solstice is considered one of the traditional Chinese holidays.