All life on Earth is determined by the proximity to the Sun and the movement of the planet around it and around its own axis. A year is the time during which our planet flies around the Sun, and a day is the time for a complete revolution around its axis. Of course, it is very convenient for people to plan their affairs by weeks, to count a certain number of days in a month or a year.
Nature is not a machine
But it turns out that for a complete revolution around the Sun, the Earth rotates around its axis not the full number of times. That is, there is not a full number of days in a year. Everyone knows that this happens 365 times and this corresponds to the number of days in a year. In fact, a little more: 365, 25, that is, an extra 6 hours accumulate in a year, and to be completely accurate, an extra 5 hours, 48 minutes and 14 seconds.
Of course, if this time is not taken into account, then the hours will add up in a day, those in months, and in a few hundred years the difference between the generally accepted and astronomical calendar will be several months. For social life, this is completely unacceptable: all holidays and memorable dates will be moved.
Similar difficulties were discovereda long time ago, even under the Roman emperors, or rather, under one of the greatest of them - Gaius Julius Caesar.
Caesar's order
Emperors in ancient Rome were revered on a par with the gods, had unlimited power, so they just remade the calendar with one order, and that's it.
In ancient Rome, the whole year was based on the celebration of calends, non and ides (as the parts of the month were called). The last month of the year was February. Thus, in a leap year, there were 366 days, and the extra days were in the last month.
After all, it was quite logical to add a day in the last month of the year, in February. And, interestingly, not the last day was added, as it is now, but an additional day before the calendars of the month of March. Thus, in February there were two twenty-fourths. Leap years were appointed after three years, and the first of them happened already during the life of Caesar Gaius Julius. After his death, the system got a little off because the priests made a mistake in the calculations, but over time the correct calendar of leap years was restored.
Leap years are now considered a bit more complicated. And this is due to those few extra minutes that are obtained by introducing a full extra day every four years.
New calendar
The Gregorian calendar, according to which secular society currently lives, was introduced by Pope Gregory at the end of the 16th century. The reason the new calendar was introduced is because the old countdowntime was inaccurate. By adding a day every four years, the Roman ruler did not take into account that in this way the official calendar would be ahead of the generally accepted one by 11 minutes and 46 seconds every four years.
At the time of the introduction of the new calendar, the inaccuracy of the Julian was 10 days, over time it has increased and is now 14 days. The difference increases every century by about a day. It is especially noticeable on the day of the summer and winter solstices. And since some holidays are counted from these dates, the difference was noticed.
The Gregorian leap year calendar is a bit more complicated than the Julian one.
Structure of the Gregorian calendar
The Gregorian calendar takes into account the difference in the official and astronomical calendar of 5 hours, 48 minutes and 14 seconds, that is, every 100 years one leap year is canceled.
So how do you know which year is a leap year and which is not? Is there a system and algorithm for canceling an extra day? Or is it better to use a list of leap years?
For convenience, such an algorithm has indeed been introduced. In general, every fourth year is considered a leap year, for convenience, years that are multiples of four are used. Therefore, if you need to find out whether the year of your grandmother's birth or the start of World War II was a leap year, you just need to find out whether this year is divisible by 4 or not. So 1904 is a leap year, 1908 is also a leap year, but 1917 is not.
The leap year is canceled when the century changes, that is, in a year that is a multiple of 100. Thus, 1900 was not a leap year, becausethat it is a multiple of 100, common years are also 1800 and 1700. But an extra day does not accumulate in a century, but in about 123 years, that is, again it is necessary to make amendments. How do you know which year is a leap year? If a year is a multiple of 100 and a multiple of 400, it is considered a leap year. That is, 2000 was a leap year, just like 1600.
The Gregorian calendar, with such complex adjustments, is so accurate that there is extra time left, but we are talking about seconds. Such seconds are also called leap seconds, so that it is immediately clear what it is about. There are two of them a year and they are added on June 30 and December 31 at 23:59:59. These two seconds equalize astronomical and universal time.
How is a leap year different?
Leap year is one day longer than usual, it has 366 days. Earlier, back in Roman times, this year there were two days on February 24, but now, of course, the dates are counted differently. This year in February there is one more day than usual, that is, 29.
But years that have February 29th are considered unlucky. There is a belief that in leap years the death rate rises, various misfortunes occur.
Happy or unlucky?
If you look at the mortality chart in the USSR in the second half of the 20th century and in Russia, you can see that the highest level was recorded in 2000. This can be explained by economic crises, low living standards and other problems. Yes, 2,000 was a leap year (since it's divisible by 400), but is that the rule? 1996 is not a record holder at allmortality rate was higher in 1995 before it.
The minimum mark for almost half a century, this figure reached in 1987. The year is not a leap year, but in 1986 the mortality was also low, much lower than, for example, in 1981.
There are many more examples, but it is already clearly seen that mortality does not increase in “long” years.
If you look at the birth rate statistics, you can't find a clear relationship with the length of the year either. Leap years of the 20th century did not confirm the theory of misfortune. The birth rate both in Russia and in European countries is falling evenly. A slight rise is observed only in 1987, and then the birth rate begins to grow steadily after 2008.
Maybe a leap year determines some tension in politics or predetermines natural disasters or wars?
Among the dates of the beginning of hostilities, you can find only one leap year: 1812 - the war with Napoleon. For Russia, it ended quite happily, but, of course, it was a serious test in itself. But neither the year of the revolution of 1905 nor 1917 was a leap year. The year the Second World War began (1939) was by far the most miserable year for all of Europe, but it was not a leap year.
In leap years, earthquakes occurred in Armenia and the explosion of the hydrogen bomb, but events such as the Chernobyl disaster, the tragedy in the Japanese cities of Hiroshima and Nagasaki, volcanic eruption and other disasters happened in the most ordinary years. List of leap years in the 20thcentury does not at all coincide with the mournful list of misfortunes and catastrophes.
Causes of unhappiness
Psychologists believe that all statements about the fatality of a leap year are nothing more than superstition. If it is confirmed, they talk about it. And if it is not confirmed, they simply forget about it. But the expectation of misfortune in itself can “pull” trouble. It is not for nothing that often what happens to a person is exactly what he is afraid of.
One of the saints said: "If you do not believe in omens, they will not be fulfilled." In this case, this is most welcome.
Jewish leap year
The traditional Jewish calendar uses lunar months that last 28 days. As a result, the calendar year according to this system lags behind the astronomical one by 11 days. An additional month in the year is regularly introduced for adjustment. A leap year in the traditional Jewish calendar consists of thirteen months.
Leap year for Jews is more common: out of nineteen years, only twelve are common, and another seven are leap years. That is, the Jews have much more leap years than in the usual case. But, of course, we are talking only about the traditional Jewish calendar, and not about the one according to which the modern state of Israel lives.
Leap year: when next
All our contemporaries will no longer face exceptions in the calculation of leap years. The next year, which will not be a leap year, is expected only in 2100, this is hardly relevant for us. So the next leap year can be calculated very simply:the next year, which is divisible by 4.
2012 was a leap year, 2016 will also be a leap year, 2020 and 2024, 2028 and 2032 will be leap years. It is quite easy to calculate this. Of course, it is necessary to know this, but do not let this information scare you. And in a leap year, wonderful and joyful events happen. For example, people born on February 29th are considered lucky and happy.
