How long does a leap year last? Leap years

Every 4 years, humanity lives in a leap year. It is this year, in February, that magically becomes 29 days.

There are many signs and beliefs associated with it, many of which have pagan roots, but there are also Christian elements. Sometimes, it comes to the point that during a leap year people give up such usual activities as a seaside holiday or regular trips to the country.

What is a leap year and how valid are the signs associated with it?

Leap year: where did the extra day come from?

Do you think that the Earth makes a full revolution in exactly 365 days? No, this is not so - the Earth makes a full circle around the Sun a little longer, namely, 365 days and 6 hours.

In other words, every year an extra quarter of a day is added. Over the course of 4 years, such quarters last 24 hours. So it turns out that a year that is divisible by 4 (2008, 2012, 2016, the leap year calendar is based on this principle) is different from the rest.

The leap year is designed to eliminate this surplus and bring balance to the calendar. If it were not for the leap year, then in a couple of centuries the new year would have moved to the beginning of March, and this is quite serious!

Leap year differences

The differences between a leap year and other years, from a material point of view, are limited only by the number of days. In addition, people have to work one more day. Sometimes, however, it turns out to take an extra rest, but this happens quite rarely.

From an astrological point of view, during the Earth's path around the Sun during a leap year, a large number of troubles occur:

• people's everyday problems;
• man-made disasters;
• natural disasters;
• relatively high mortality rate.

However, one can argue with the latter - there are no comments from funeral service workers about the increase in mortality. Only slightly more elderly people die.

Leap year: greetings from Antiquity

For the first time, the ancient Romans became concerned with the problem of the calendar not corresponding to the real flow of time. In this country it was forbidden to transfer significant dates to another time of the year. People were guided by the movement of the Sun across the sky.

Guy Julius Caesar solved the problem quickly and radically - from the moment of his reign, people began to live according to the Julian calendar, which added one day to February every 4 years. The transition to the new calendar began gradually, not everyone accepted it, but time took its toll.

Over time, the pagan calendar migrated to Christian culture. But in some regions this year is associated with Kasyan Visokos, one of the saints, the patron saint of monasticism.

Allegedly, he binge-drinks for three years, and after 4 years he comes out of the drinking binge and takes it out on people for the fact that his day is celebrated only once every 4 years.

Here, however, there is a problem - a Christian saint, by definition, cannot be a binge drunkard, plus there is no record in the church that Visokos likes to drink.

Signs and beliefs associated with leap year

Nowadays, leap year is treated relatively simply, but in the past, some people were afraid to leave the house on February 29th during a leap year. For example, there was a superstition that if you were very cold on this day, and at the end of February the frosts could be severe, then a person would certainly catch a severe cold and die.

The same applies to livestock. Popular belief says that any mistake in caring for pets on this day can cost the animals their lives. For example, malnutrition or overfeeding.

Starting a new business in a leap year, according to popular belief, cannot bring much success.

Everything is bound to go wrong: even if a person builds a house, or even opens a business. In addition, all major matters should be postponed at least until February 29 - this time is considered the most unfortunate since the beginning of the year.

To appease Visokos a little, you need to do the following:

• when the chimes strike, throw a glass of vodka out of the window (other alcohol will do, but it must be strong);
• drink without clinking glasses when it is exactly midnight;
• If you still clink glasses, then before you take a sip, you need to put the glasses on the table.

According to popular belief, Visokos's anger will subside a little before the completion of the next track around the Sun.

Another interesting sign is associated with collecting gifts from nature. Usually, picking mushrooms and berries is difficult on February 29, but things found on the street, for example, money, can bring trouble if they get into the house.

And if at the same time the dog howls (Dog Day on February 29 is itself a bad sign), then disaster is guaranteed. You need to ignore him, saying, “Forget me.”

Leap year prohibitions

Since this year is so unlucky, people have come up with many prohibitions, by observing which you can ward off trouble from your home. By the way, nature also “participates” in these prohibitions.

For example, according to the recollections of old-timers, in leap years there is usually a weak harvest of apples.

So, what not to do in a leap year:

• You can't sing carols at baptism. This ritual itself is relatively associated with evil spirits, and once every four years they are especially “attentive” to people. It's better not to attract any rubbish. So no matter how many sweets people offer, it is better to avoid carols.
• It is not recommended to sell products produced on your own farm. It is believed that happiness and wealth leave the house with them.
• You shouldn’t show your baby’s first tooth that has erupted to anyone, except perhaps your closest relatives. If you break the ban, the child will have crooked teeth.
• You cannot start new big things, including getting married. Everything will go wrong, this has already been discussed above.
• You can’t buy “coffin things.” It sounds strange, but for some older people it is the norm to buy things for their funeral. Such an action during a leap year will hasten death.
• Women are strictly prohibited from dyeing their hair. This can lead to the lady going bald.
• Changing your place of work or place of residence is prohibited. A person simply will not get accustomed to a new place; he will have to start everything from scratch (this point is sometimes impossible, because there are different circumstances in life).

Having children joins this forbidden group, but not everyone takes this restriction seriously.

Maybe this all sounds archaic, but the fact remains that people often complain to astrologers and psychics about misfortunes that began precisely after violating such prohibitions.

Conclusion - until the Earth makes a full revolution around the Sun in a leap year, some activities should be abandoned.

What do astrologers think?

In 2016, I made an anonymous personal calendar for a young man. He was going to start a new business project, but numerology showed that the undertaking would not only be extremely unsuccessful, but could even lead to the death of my client.

Unfortunately, he didn’t listen to me, he did the opposite. The result is deplorable - although he remained alive, he lost everything to the last penny, and is now starting a new life.

Surprisingly, most of these calendars for different people, made during leap years, showed similar results. I don’t really believe in the involvement of negative entities in the problems, but the influence of the planets in these years is extremely negative.

The leap year should pass calmly and without unnecessary movements, I can tell you that for sure!

Irina, Moscow

All the predictions I made for people wanting to get married on a leap year didn't say anything good. This time is a time of failures, misunderstandings, conflicts and contradictions, what kind of marriage can we talk about?

At the same time, many of these “weds” separated even before the wedding. Since 2016, only 5-10% of those families have survived.

Mortality, by the way, is also increasing! Older people die in droves during leap years. Pray more often, do not anger the higher powers! And go to church, every 7 days or so.

Svyatoslav, Yaroslavl

I believe that leap year is a pagan Slavic belief. The ancestors endowed February with demonic power and feared it like fire.

So this belief has come to us in a greatly modified form. There's nothing wrong with a leap year, but a little care still wouldn't hurt.

Irma, Moscow

High mortality, that's what a leap year is. It is rare to make favorable forecasts at this time.

Basically, people have some problems to solve. I advise you not to violate the leap year prohibitions and undergo purification rituals more often.

Svetlana, Samara

2016 is a leap year. This is not such a rare occurrence, because every 4 years the 29th day appears in February. There are many superstitions associated with this year, but is it really so dangerous? Let's try to figure this out, whether leap years are different in any way. The 21st century list regarding leap years is maintained on the same principle as before.

Leap year: definition

We all know that there are 365 days in a year, but sometimes there are 366. What does this depend on? First of all, it should be noted that we live according to the Gregorian calendar, in which those that contain 365 days are considered ordinary years, and leap years are those that are one day longer, respectively 366 days. This happens because periodically in February there are not 28, but 29 days. This happens once every four years, and this very year is usually called a leap year.

How to determine a leap year

Those years whose numbers can be divided without a remainder by the number 4 are considered to be leap years. A list of them can be found in this article. Let's say the current year is 2016, if we divide it by 4, then the result of division is a number without a remainder. Accordingly, this is a leap year. In a normal year there are 52 weeks and 1 day. Each subsequent year shifts by one day in relation to the days of the week. After a leap year, the shift occurs immediately by 2 days.

The astronomical year is counted from the first day of the vernal equinox to the beginning of the next. This period, precisely, does not have exactly 365 days, which are indicated in the calendar, but several more.

Exception

The exception is the zero years of centuries, that is, those with two zeros at the end. But if such a year number can be divided without a remainder by 400, then it is also considered a leap year.

If we consider that the extra hours in a year are not exactly six, then the missing minutes also affect the calculation of time. It was calculated that for this reason, in 128 years, one extra day would pass in this way. In this regard, it was decided that not every fourth year should be considered a leap year, but that those years that are divisible by 100, except those that are divisible by 400, should be excluded from this rule.

The history of the leap year

To be more precise, according to the Egyptian solar calendar, introduced by Julius Caesar, the year has not exactly 365 days, but 365.25, that is, plus another quarter of a day. The extra quarter of a day in this case is 5 hours 48 minutes and 45 seconds, which was rounded up to 6 hours, constituting a quarter of the day. But adding such a small unit of time to the year every time is impractical.

Over four years, a quarter of a day turns into a full day, which is added to the year. So February, which has fewer days than normal months, adds an extra day - and only a leap year has a February 29th.

Leap years: a list of years from the past and the 21st century. Example:

It was decided to adjust the calendar year in accordance with the astronomical year - this was done so that the seasons always occurred on the same day. Otherwise, the boundaries would shift over time.

From the Julian calendar we switched to the Gregorian calendar, which differs from the previous one in that a leap year occurs once every four years, and according to the Julian calendar - once every three years. The Russian Orthodox Church still lives according to the old style. It is 13 days behind the Gregorian calendar. Hence the celebration of dates according to the old and new styles. Thus, Catholics celebrate Christmas according to the old style - December 25, and in Russia according to the Gregorian calendar - January 7.

Where did the fear of a leap year come from?

The word "leap year" comes from the Latin phrase "bis sextus", which translates as "second sixth".

Most people associate leap year with something bad. All these superstitions go back to Ancient Rome. In the modern world, days are counted from the beginning of the month, but in ancient times it was different. They were counting the days left until the beginning of the next month. Let’s say, if we say February 24, then the ancient Romans in this case used the expression “the sixth day before the beginning of March.”

When a leap year occurred, an additional day appeared between February 24 and 25. That is, in a normal year there were 5 days left until March 1, and in a leap year there were already 6, which is why the expression “second sixth” came about.

With the onset of March, the fast ended, which lasted five days, if you start from February 24, but when you add an extra day, the fast already lasted, accordingly, 1 day longer. Therefore, they considered such a year to be bad - hence the superstition about the unluckiness of leap years.

In addition, the superstition comes from the fact that only in a leap year is Kasyanov’s Day celebrated, which falls on February 29. This holiday is considered mystical. In this regard, for a long time people have been trying not to do big things in such years, not to get married, not to have children, etc. Despite the simplicity of the algorithm for determining a leap year, some may wonder: “Which years are leap years?”

Leap years of the 19th century: list

1804, 1808, 1812, 1816, 1820, 1824, 1828, 1832, 1836, 1840, 1844, 1848, 1852, 1856, 1860, 1864, 1868, 1872, 1876, 1880, 1884, 1888, 1892, 1896.

Leap years of the 20th century: their list is as follows:

1904, 1908, 1912, 1916, 1920, 1924, 1928, 1932, 1936, 1940, 1944, 1948, 1952, 1956, 1960, 1964, 1968, 1972, 1976, 1980, 1984, 1988, 1992, 1996

What years are leap years? The list of years of the current century will be constructed similarly to the previous ones. Let's take a look at it. Leap years (list) of the 21st century will be calculated in the same way. That is, 2004, 2008, 2012, 2016, 2020, etc.

Signs associated with leap year

This year, according to legend, you cannot change your usual environment. This can be understood as moving to a new place of residence, looking for a new job.

It was believed that marriages entered into this year could not bring happiness, and weddings were not recommended.

You also can’t do anything, start new things. This includes opening a business or building a house.

Let's answer the question: which years are leap years? List of 19th, 20th and 21st centuries:

It is better to postpone long trips and travel.

You can't celebrate your baby's first tooth.

Since ancient times, such years were considered dangerous, bringing many deaths, diseases, wars and crop failures. People, especially superstitious ones, fear the onset of such a year, having already prepared in advance for the worst. But are they really that dangerous?

Opinion about established superstition

The Church does not see anything bad in these years, explaining the phenomenon of a leap year as just changes in the calendar that were once made. Based on statistics, such years are no different from ordinary ones. Even if we take the issue of marriage in a leap year, which predicts a short life in marriage, then the number of divorces of “leap marriages” is no greater than among those couples who got married in ordinary years.

How many days are there in a leap year?

Once every four years we observe an interesting calendar phenomenon. It is customary for us to count 365 days every year, but once every four years we count 366 days. This has happened historically, since 45 BC, when a Roman dictator named Gaius Julius Caesar created the calendar. Later, such a calendar began to be called the Julian.

The history of the leap year.

The new calendar of Gaius Julius Caesar began on January 1, 45 BC. Astronomers of that time calculated the exact number of days during which the Earth completely goes through a cycle called a year. The exact number of days was 365.25. In other words, there were 365 full days and 6 hours in a year. Since it was inconvenient to count less than a full day, we decided to introduce a special one to even out the balance.

For three years in a row, 365 days are counted, and in each subsequent fourth, 24 hours are added (6 hours in 4 years) in February. Thus, a new day of February appeared, only one, appearing every four years. This month was not chosen by chance. It was considered the last Roman month of the year. The year 45 BC became the first leap year.

The current year 2016 is a leap year. The next one will be in 2020, then in 2024, etc.

Signs of a leap year.

Since ancient times, a year in which there are one day more than in other years was considered significant and even difficult. Some events were associated with it; it was believed that if in this particular year winter is a day longer, it means that this year affects the human body in a special way.

Leap year, signs which many people are scared of, is actually not that scary. The human body is not designed for changes in the calendar and numbers. Rather, a person runs the risk of being influenced by the location of the planets, the moon and other external factors that affect the person as a whole.

Among the signs that many people have during this long year, the main ones are prohibitions on various buildings.

Leap year: what not to do?

Many of us are interested in what cannot be done on a leap year. Among these activities are:

• caroling,
• make real estate transactions,
• divorce.

It is not recommended to travel far, and if this happens, it is advised to say certain prayers. All this, of course, has nothing to do with religion, so if the soul asks for prayer, it is better to pray without any signs.

Leap year is not a big deal.

A year like this can bring a person many wonderful moments. In leap years, such great figures of art and culture were born as: M. Glinka, I. Strauss, L. Tolstoy, I. Goncharov, as well as modern actors: K. Diaz, K. Khabensky, T. Hanks.

I hope you had a great New Year and are in a great holiday mood right now. At least that’s how it is for me - we didn’t drink any alcohol, and clinked glasses of water from a five-liter canister at midnight, so we woke up, took a walk, and then I remembered one of yesterday’s Happy New Year greetings:

I wish that at the end of each year, remembering what happened over the last 366 if ((year%4 == 0 and year%100 != 0) or (year%400 == 0)) else 365 days, think about myself:

Oh, wow, what an action that was. I will definitely tell my grandchildren or write a book about it later.

For example, 2013 is not a leap year, 1700, 1800 and 1900 are again not leap years, but 2000, 2004, 2008 and 2012 are leap years.

But what if we don't remember how many days there are in leap years (366 days) and non-leap years (365 days), or we just want to write the definition of the number of days in a year as quickly as possible? Is it possible to do this in Python? Of course you can.

So Python has a calendar module. It is perfect for finding out whether a year is a leap year (or, for example, how many leap years there are in a certain interval), determining the number of days in a month, getting the number of the day of the week for a certain date, and so on.

In particular, we can get the number of days in each month of the year and simply add them up.

The calendar.monthrange function takes the year number as the first argument and the month number as the second argument. Returns the number of the day of the week on the first day of the given month and the number of days in the given month:

>>> import calendar >>> calendar.monthrange(2013, 1) (1, 31)
Accordingly, we can calculate the total number of days for all 12 months, and thus obtain the number of days for a given year:

>>> import calendar >>> year = 2013 >>> sum(map(lambda x: calendar.monthrange(year, x), range(1, 13))) 365
But if you think about how exactly this line is executed, it becomes obvious that this solution is very inefficient if you need to count the number of days for a large number of years.

We check using the timeit module.

To perform it 1 million times, it takes 13.69 seconds if import calendar is done once at the beginning. If import calendar is done every time then 14.49 seconds

Now let's try another option. It requires knowing how many days there are in leap and non-leap years, but it is very short:

>>> import calendar >>> year = 2013 >>> 365+calendar.isleap(year) 365
And, as you can easily guess, it is already much faster: 0.83 seconds, including import calendar, and 0.26 seconds if import calendar is done once at the beginning.

Let's also see how long the very first option takes, with a "manual" approach: 0.07 seconds for 2012 and 2013 and 0.12 seconds for 2000 (I think everyone understands where such a difference in speed comes from for these years).

It turns out that this is the fastest option of these three:

>>> import calendar >>> year = 2013 >>> 366 if ((year%4 == 0 and year%100 != 0) or (year%400 == 0)) else 365 365
Of course, in most cases you can use any of these options - after all, when determining the number of days in one, two, ten or a hundred years, you are unlikely to notice any difference.

Write, optimize, improve, test and measure performance - but don't forget about the readability of the source code of your programs.

Happy New Year! Good luck, happiness, joy and self-improvement in the new year.

sharky:
03/25/2013 at 16:04

Why on earth is 1900 not a leap year? A leap year occurs every 4 years, i.e. If it is divisible by 4, it is a leap year. And no more divisions by 100 or 400 are needed.

It’s normal to ask questions, but before you assert anything, study the hardware. The Earth revolves around the sun in 365 days 5 hours 48 minutes 46 seconds. As you can see, the remainder is not exactly 6 hours, but 11 minutes 14 seconds less. This means that by making a leap year we add extra time. Somewhere over 128 years, extra days accumulate. Therefore, every 128 years in one of the 4-year cycles there is no need to make a leap year in order to get rid of these extra days. But to simplify things, every 100th year is not a leap year. Is the idea clear? Fine. What then should we do next, since an extra day is added every 128 years, and we cut it off every 100 years? Yes, we cut off more than we should, and this needs to be returned at some point.

If the first paragraph is clear and still interesting, then read on, but it will be more difficult.

So, in 100 years, 100/128 = 25/32 days of excess time accumulates (that’s 18 hours 45 minutes). We do not make a leap year, that is, we subtract one day: we get 25/32-32/32 = -7/32 days (that’s 5 hours 15 minutes), that is, we subtract the excess. After four cycles of 100 years (after 400 years), we will subtract an extra 4 * (-7/32) = -28/32 days (this is minus 21 hours). For the 400th year we make a leap year, that is, we add a day (24 hours): -28/32+32/32=4/32=1/8 (that’s 3 hours).
We make every 4th year a leap year, but at the same time every 100th year is not a leap year, and at the same time every 400th year is a leap year, but still every 400 years an extra 3 hours are added. After 8 cycles of 400 years, that is, after 3200 years, an extra 24 hours will accumulate, that is, one day. Then another mandatory condition is added: every 3200th year should not be a leap year. 3200 years can be rounded up to 4000, but then you will again have to play with added or trimmed days.
3200 years have not passed, so this condition, if it is made this way, is not yet talked about. But 400 years have already passed since the approval of the Gregorian calendar.
Years that are multiples of 400 are always leap years (for now), other years that are multiples of 100 are not leap years, and other years that are multiples of 4 are leap years.

The calculation I gave shows that in the current state, an error in one day will accumulate over 3200 years, but here’s what Wikipedia writes about it:
“An error of one day compared to the year of the equinoxes in the Gregorian calendar will accumulate in approximately 10,000 years (in the Julian calendar - approximately in 128 years). A frequently encountered estimate, leading to a value of the order of 3000 years, is obtained if one does not take into account that the number of days in the tropical year changes over time and, in addition, the relationship between the lengths of the seasons changes.” From the same Wikipedia, the formula for the length of a year in days with fractions paints a good picture:

365,2425=365+0,25-0,01+0,0025=265+1/4-1/100+1/400

The year 1900 was not a leap year, but 2000 was, and special, because such a leap year happens once every 400 years.