Many people want to understand when the leap year will occur. This desire is due to the desire to realize how dangerous the upcoming not 365, but 366 days. Moreover, it is generally accepted that the coming leap year threatens with numerous dangerous events and serious disasters. Is this situation really true? Should we indulge the many experiences that are created on the basis of superstition?
Some facts from history: how did leap year appear?
The leap year appeared thanks to the formation of the Julian calendar back in the 1st century BC. Thanks to numerous calculations, Alexandrian astrologers were able to determine the exact length of the astronomical year, which is 365 days and six hours. 
Julius Gaius Caesar, back in 445 BC, developed a calendar that he called the Julian. It should be noted that Julius Caesar is a famous emperor, dictator and commander, thanks to whom the history of the whole world has changed dramatically, including the emergence of leap years, which are even.
After it was possible to accurately determine the length of the astronomical year, it turned out that it was not clear what to do with six hours, because they could not be included in the total number of days. As a result, an extraordinary decision was made: three years were to consist of 365 days. These six hours had to accumulate over four years in order for the fourth year to become a leap year and have 366 days. Moreover, the increased number of days always falls in February: 28 days (non-leap) and 29 days (leap).
Thus, the tradition regarding a leap year, which should be every fourth year, has existed since 445 BC.
Algorithm for determining leap year.
So, in 1582, people began to follow the new Gregorian calculus, which only led to complex calculations. Now, in order to understand which year promises to be a leap year, you need to carry out serious calculations. This is due to the following nuance: scientists were calculating not the astronomical, but the solar period, which fell in the interval between the two spring equinoxes.
Scientific techniques made it possible to carry out special calculations. It turned out that every year the time shift occurs not at 6.00, but at 5 hours 48 minutes 46 seconds. Thus, a leap year must be a multiple of four, with a few exceptions. For this reason, calculations have become more difficult.
Ordinal numbers that ended in two zeros were considered non-leap numbers if they could not be divided by exactly four hundred.
Thus, two cases are assumed to allow the calculation of a leap year:
- The year number is divisible by 4, but cannot be divisible by 100.
- The sequence number can be divided by 400.
Taking into account the peculiarities of calculations, the transition of centuries ending in 00, in three cases out of four, should not be a leap year. 
What are the characteristics of a leap year?
Leap and non-leap years have important differences:
- The number of days in a leap year should be 1 more than in a regular year: 366, not 365.
- In February the 29th appears. Moreover, in non-leap years the number of days in February is 28.
- Based on popular beliefs, during a leap year, mortality, as well as the number of accidents of various types, increases.
In any case, popular beliefs say what should not be done during a leap year in order to avoid excessive risks.
What should you not do during a leap year?
- Carols should be abandoned. It is believed that people can attract increased attention from evil spirits to themselves.
- You can't talk about plans. Otherwise, your luck will run out.
- A pregnant woman should not have her hair cut, especially if she is expecting a baby during a leap year. Otherwise, the baby will be born weak.
- In a leap year, you cannot invite guests when the baby’s first tooth appears. This is demonstrated by concern for the baby's health.
- During a leap year, you cannot sell pets or livestock. Otherwise people will face poverty.
- You can't get divorced during a leap year.
- Frequent job changes are prohibited.
- You cannot exchange housing.
- You cannot build a bathhouse.
Despite numerous prohibitions and warnings, a leap year is distinguished only by an additional day. Each person can independently decide whether to believe folk signs and how to live a leap year.
One of my first more or less serious computer programs, still in the Pascal language, was a task to check whether the year is a leap year. It seems so simple - but it turned out that there are a lot of different conditions to check! I had to read a lot to figure it out what is a leap code and how to find out if the year will be a leap year.
Which year is considered a leap year?
A leap year is one in which another winter day is added every four years - February 29.
Everyone usually thinks that There are 24 hours in a day. Such days per year– time of a complete circle of the Earth relative to the Sun – runs 365 point plus small tail - approx. 6 o'clock. Over four years, a whole day is collected from such leftovers, which is “glued” to February.
The problem is that adding a whole day every 4 years– this is also a slight rounding. And over time it leads to small error.
To get rid of it, they introduced another correction, after which final algorithm looks like this:
- Is being checked Is the number of the year divisible by four without a remainder?
- If yes, and the year ends with two zeros(2100, for example, or 2700) – it won't be a leap year.
- But if it is divisible by 4, ends in two zeros and is also completely divisible by 400, it is still a leap year(like, say, the year 2000 or 2800).
At first, such complexities make your brain boil. But in reality, everything is not so difficult.
February 29 and social networks
What are they doing? social networks with notifications to birthday friends? Are people who were not lucky enough to celebrate the holiday anyway? once every four years, sitting there, forgotten by all friends and acquaintances? After all, these days it is no longer customary to write down dates in notebooks - everyone uses reminders on their phones or website tips.
If I were the birthday boy, I would be a little upset by this turn of events. In the end, even I, as a schoolgirl, was able to solve such a problem. And even more so, professional programmers must be able to approach a task carefully and thoroughly, especially when it comes to someone’s holiday.
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This is a year whose duration is one day longer than usual. In countries living on the Julian calendar, every fourth person is like this; living Gregorian - every fourth, an additional multiple of one hundred. In 1924, the New Julian calendar was developed, where everything is even more complicated - a year is considered a leap year if it is divisible by four and not divisible by one hundred, or divisible by nine hundred with a remainder of two hundred or six hundred.
And back in 1990, a rock band appeared in Fryazino, taking the name “Leap Year”.
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I was probably 8 or 9 years old when I learned about the existence of leap years. Then it immediately became interesting why a year usually contains 365 days, but sometimes a day more. At the same time, I did not limit myself to asking my parents, but took an encyclopedia from the shelf, where I found detailed information.
What are leap years?
Probably, all people know that 1 year contains 365 days, but in a leap year there are 366 of them. But not every person knows that the Earth does not make a full revolution around the Sun in such a time.
The approximate time it takes our planet to complete a full revolution around its star is 365 days and 6 hours. This is natural, because nature did not adapt to the cultural characteristics of people.
6 hours is, in turn, 1/4 of a day. And over 4 years, exactly 1 day accumulates, which it was once decided to add to February.
Interestingly, the concept of a leap year was introduced into the Julian calendar, which was adopted by Julius Caesar. And the Roman emperor himself survived only 1 leap year.
Changing the calendar
In fact, the error is somewhat larger. One real year is equal to 365 days, 5 hours and 49 minutes. The error seems insignificant, but in fact it is important. That is why at the end of the 16th century a new calendar was adopted - the Gregorian - and we live by it.
The mistake in the old calendar was that it did not take into account those 11 minutes. Therefore, over the course of several centuries, the day of the equinox shifted 10 days back relative to March 21.
A reform was carried out. In accordance with it, if the year is divided by:
- 400 - it was recognized as a leap year;
- 4 - also leap year;
- 100, but not 400 - non-leap (in Julian - yes).
As a result of this reform, the calendar year began to more fully correspond to the solar year.
But it should be understood that the Earth does not make a full revolution around the Sun in exactly 365 days, 5 hours and 49 minutes. There are also seconds and fractions of a second during which this happens. Therefore, although not soon, the existing calendar will still have to be reviewed and adjusted.
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I was born in February. Of course, this month is the most unusual among all the others. First of all, by the number of days. There are only 28 of them, instead of the usual 30 and 31. But it is mobile. Sometimes an extra day is assigned to it. Why is this happening? This question has bothered me since childhood, so I know very well what a leap year is and where it came from.
Why is February getting longer?
A leap year, simply put, is when February is 29 days long. But why?
In ancient Rome, priests calculated that a year is 365 days. The calculation was carried out on the days of the equinox, when the light and dark times of the day are equal. But then people realized that something had gone wrong. Every four years this date shifted forward one day.
Having easily counted, they determined that a year is equal to 365 whole days and one quarter of a day. Although they did not yet know about the rotation of the Earth, this is explained precisely by the fact that the planet makes one revolution around the Sun a little faster than in a calendar year.
Then Julius Caesar ordered to add an extra day every four years, compensating for the difference. This is how a year of 366 days appeared.
Differences between the Julian and Gregorian calendars
As far as I understand, the ancient scientists were wrong. The true duration of a revolution around the Sun is 365 days, 5 hours and 49 minutes. Which is 11 minutes shorter than what the Romans once calculated. Because of this, by the 16th century the equinox shifted by 10 days.
Then Pope Gregory XIII introduced a new, Gregorian, calendar, according to which, once every four centuries, a leap year became normal, which made it possible to eliminate the differences. According to this calendar, the following years are not leap years:
- 1600;
- 2000;
- 2400.
All of Europe quickly changed the calendar, which Russia did not. Because of this, by the way, such a difference in dates appeared in pre-revolutionary times, which was compensated by the transition to the Gregorian calendar at the beginning of the 20th century.
Thus, a leap year is not simply associated with an extra date on the calendar. The reason for it is complex astronomical processes!
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Once a new girl, Nelya, came to our kindergarten, and we instantly became friends. She also said that she was born on February 29th. Therefore, the day before, I spent the entire evening diligently gluing a card for her from colored paper. And in the morning my mother congratulated me on the first day of spring. In response, she heard an uncontrollable roar, as I decided that I had slept through my best friend’s birthday.
What is the difference between a leap year?
That's how I learned that our earth revolves around the sun in 365 days with a small tail of just over 6 hours. Even in 10 years this will not be particularly noticeable... But sooner or later this may lead to us celebrating the New Year in the summer. That’s why, at the end of the last era, they decided to introduce one extra day in February so that the calendar would remain “in its place.”
365 days of Egypt
But in Ancient Egypt they knew about this, but did not want to change anything. Because the last 5 days of the year were dedicated to the 5 main gods. And the shift in the calendar led to the fact that the “divine” days began to “wander.” Thus, the gods had an additional “personal” day. Therefore, changing the countdown of days was prohibited by law.
Things you didn't know about leap years
Here are some little-known facts about leap year:
- the ruler of Egypt, Euergetes Ptolemy, introduced a leap year long before Caesar, but the priests canceled this decision after his death;
- in France you can get a hundred-year subscription to a humorous publication for just a hundred euros, which is published only on February 29;
- Saint Patrick is not only the patron saint of Ireland, but also the one who allowed women to propose marriage themselves on February 29;
- There is a whole movement proposing to move February 29 to June 31, making it a worldwide holiday.
It is customary to tell all sorts of terrible things about leap years. But marriages concluded in other years also fall apart. And terrible disasters and wars also occur regardless of the number of days in a year. And all sorts of “mystical” coincidences can be found in any date, if there is a desire.
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I remember when I first learned that there was a leap year, I constantly asked my mother when it would come. And it was useless to tell me that it happens once every four years. Either I couldn’t remember, or I just didn’t want to, I don’t know. But I know for sure that for some reason everyone leap year I really liked the date February 29 never scared me.
Leap year. Signs
Probably many people know that in a leap year it is extremely undesirable get married or get divorced, change jobs or place of residence. But there are many more signs, small and not so small.
- It's better in a leap year Not walk carol. It was believed that by singing carols in such a year one could awaken evil spirits and bring misfortune upon oneself and one’s family;
- Not recommended to sell or give away animals from your home (this way you can distribute good luck)
- categorically Not recommended start construction at home or cottage. Even better Not start off plan construction (it is believed that such construction will either not be completed or will bring misfortune)
- I could list the signs for a long time, but believe in them or not – personal choice every person. Personally, I don’t think that every leap year will necessarily be bad, because we create our lives ourselves, and not some February 29th.
February 29 is a historical date
A little history:
- 1696 - Peter I began directing the construction of ships for the Azov campaign
- 1916 - Arthur Hale received a patent for the so-called. “clover” interchange model, which reduces the risk of an accident
- 2004 – film “The Lord of the Rings. The Return of the King won all 11 Oscars for which it was nominated.
Overdid it
There are cases in history where people tried to keep track of the calendar so diligently that they overdid it a little and ended up with another extra day - February 30th. February 30th appeared for the first time V1712 in the calendar Kingdom of Sweden. This happened because the Swedes got so confused when switching from the Julian to the Gregorian calendar that they almost got their own chronology.
Once again the 30th date appeared in February in 1929 V USSR. Then this was due to the need to divide the year into 72 five-day days due to the reform of the People's Commissar of the Soviet Union.
And there is a possibility that February 30th will have to be added to the calendar 3328, because the astronomical calendar does not coincide 100% with ours, and by that time another day will “run by”. But, unfortunately, we definitely won’t see this.
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I never believed that leap year maybe something bad. The people around me, especially those who had “seen it,” with each onset of such a period began to talk about it cautiously, and at the same time, with mistrust and hopelessness. Indeed, nothing can be done, this is a special period that tests the strength of many people. I became terribly interested: a what they are, in fact, so afraid and why?
What is a leap year and who invented it?
Word "leap" comes from Latin and means "second sixth". This is such a year in Julian(every 4 years) and Gregorian calendars(also every 4 years, but with exceptions), which counts not 365 days, but 366 . The famous Roman ruler “kneaded” it all Caesar, who introduced the Julian calendar into use in 45 BC., but they came up with it - astrologers. But, priests, which did not understand the principle of calculation and did not clarify it, they managed to “mess up”: instead of adding 1 day every 4 years, they added 1 day in February every 3 years. Only 36 years later, the ruler August the correct order was restored.
St. Oswald's Day
Few of us know about this Valentine's Day. It is celebrated every 4 years February 29 in memory of the saint Oswald, who died on this day. According to tradition, any woman can offer get married to the man in whom she unrequitedly in love. But if he will refuse, you will be required to pay fine the size of 100 pounds.
What's good about a leap year?
It sounds strange, what good can happen in a period that brings nothing but misfortune? Was noticed what exactly in leap years are born great or brilliant people culture And art:
- I. Strauss;
- M. Glinka;
- L. Tolstoy;
- I. Goncharov.
Of the modern famous people - actors T. Hanks, K. Khabensky, K. Diaz.
Psychologists' opinion about leap year
What can psychologists say? Has such a depressing pattern been confirmed by science? No. Everything is in our heads. You yourself « programmer» of your life. What we are afraid of will happen, our personal attitude for certain events. Therefore, in a leap year you need to live as you lived in previous years, without getting hung up.
Since childhood, I sincerely felt sorry for people who had a birthday. February 29. Well, how is it that a “great” holiday, by children’s standards, happens once every 4 years?!
Later, of course, it was explained to me when those who were born celebrate their birthday February 29 and, in general, what day is this.
What is the essence of leap year?
It turns out that everything is elementary... Leap yearoccurs due to the fact that the Earth does not have time to meet 365 days when flying around the sun. She should hurry up, but no! And every year the mother planet is 6 hours late.
The first year I “lost” 6 hours, the second, third, and by the fourth - already a day turned out. So the inhabitants of the Earth decided, in order not to disrupt the onset of summer and winter over time, add this day every fourth calendar year.
It turns out that A leap year is a year that is 1 day longer than its three predecessors. He counts in comparison with them 366 days.
This fact of the Earth's lag has been known for a long time, the problem was solved insertion of a leapfrog. However when comparing the tropical year(time between identical positions of the sun) with calendar, it was revealed discrepancy of 1 day after 128 years. To correct the inaccuracy, the existing calendars were corrected, achieving an error 1 day/50,000 years in the New Julian calendar.
Even though it is as accurate as possible, to my surprise, it is not widespread in the world.
What to do for birthday people
Birthday people celebrate their holiday for 3 years a day earlier or later(optional), and for the 4th year - on time. It seems to have become clear, but still I still sympathize with those born in leap day. Although they are definitely not deprived of attention.
For example:
- IN Texas organized annually celebration, which brings together from all over the world those who born February 29.
- IN Hong Kong And New Zealand the state paid attention to them and “simplified” their life, determining the date of the celebration.
- Something tells me that Zero Discrimination Day» also timed for a reason March 1.
Some believe that in additional day of the year appear most talented people. Personally, I haven’t found accurate statistics and I have little faith in it. For the same reason skeptical I am of the opinion that leap year“attracts” troubles. No more, no less good and bad things happen in it than in a year containing 365 days.
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It is known that any given year is either an ordinary year or a leap year. Why is there such a distinction, how is time counted in each case, and how does a leap year differ from a regular year? This is discussed further.
Origin of the calendar
Periods of time called years are recorded in calendars. There you can also see the division into months, weeks and small units - days. This number system has been known since the times of Ancient Egypt. Using the calendar, people calculated when the next Nile flood would occur. It was necessary to have time to repair special structures for retaining water, so as not to be left without a crop.
The original calendar was somewhat inaccurate. It did not reflect the fact that in a year, in addition to a certain number of whole days, there are almost six more hours. Some corrections to this version of time recording were made by Julius Caesar. This type of calendar is called Julian. But the most accurate was the Gregorian calendar, which appeared even later, named after the Pope, who made adjustments to the previous version. It is by this chronology system that people in most countries now live.
Comparison
The number of whole days that make up a year, which always remains the same, is 365. And those additional six-hour segments after a certain time form another day. It is not difficult to calculate that such an additional day “grows” over four years. It is customary to add it to February - the twenty-ninth appears at the end of the month. And the year in which this happens is called a leap year.
So, the difference between a leap year and a regular year is the appearance of the 366th day. But why does February periodically become longer? This is because the year used to end with this month, and not December, and it was logical to time one more day to coincide with the end of the next round of time. In addition, February is short, so an additional date will not be superfluous for it.
Interestingly, superstitious people have their own answer to the question of what is the difference between a leap year and a regular year. It is argued that the first of them is unsuccessful for any endeavors, such as starting a business or getting married. In addition, according to popular belief, a leap year promises unforeseen disasters and various misfortunes. However, you should not trust such signs too much. After all, this unusual year did not appear under the influence of some mystical force. It was invented by people themselves for a more accurate calculation of time.
05.08.2017 18:25
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Everyone knows that a year is divided into 12 months. Each month has 30 or 31 days, except for February, which usually has 28 days. The total number of days in a year is 365. But every four years this figure changes, increasing to 366. In February there is one more day, and we see the 29th on the calendar. Why is this happening?
In 45 BC, astronomers from Alexandria compiled a calendar by order of the ancient Roman commander Gaius Julius Caesar. In this calendar, the year consists of 365 days and 6 hours. In exactly this period, the Earth goes all the way around the Sun. To compensate for this six-hour difference, another day is added every 4 years in February.
Checking whether a year is a leap year or not is very simple. It is necessary to divide its number by 4. The answer should be obtained in the form of a number without a remainder.
Some people consider leap year difficult and unlucky. Where did this superstition come from? The fast ended at the beginning of March, and in a leap year it increased by one day. Therefore, people thought that the year would be difficult. The superstition was also reinforced by the holiday Kasyanov Day, which is celebrated on February 29. According to one of the folk tales, Kasyan was an angel who knew a lot about what God was doing. But he turned out to be a traitor and told everything he knew to the demons. As punishment, he was beaten on the forehead every three years, and in the fourth year he was released to Earth. There he committed various atrocities. There is also a version that Kasyan was a saint. Having violated the ban, he drank alcohol every 3 years, and stopped on the fourth. Therefore, people believed that during a leap year one should not do any important things, such as build a house or get married. But the Orthodox Church denies all these superstitions, arguing that a leap year, according to statistics, is no different from an ordinary year.
