Leap years: list, calendar. When is the next leap year?

All life on Earth is determined by the proximity to the Sun and the motion of the planet around it and around its own axis. The year is the time for which our planet flies around the Sun, and the day is the time of full revolution around its axis. People, of course, are very comfortable planning their business for weeks, counting 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 a full number of times. That is an incomplete 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, for a year, runs extra six hours, and if to be quite accurate, then extra 5 hours, 48 minutes and 14 seconds.

Naturally, if this time is not taken into account, then the clock will fold in a day, those in months and in a few hundred years the difference between the conventional and astronomical calendar will be in a few months. For social life, this is absolutely unacceptable: all holidays, memorable dates will move.

Similar difficulties were discovered a long time ago, even under the Roman emperors, or rather, with one of the greatest of them - Gae Julius Caesar.

The Order of Caesar

The emperors in ancient Rome were revered on a par with the gods, had unlimited power, so they simply changed the calendar with one order, and that's it.

In ancient Rome, the whole year was built on the basis of the celebration of calends, non and id (the so-called parts of the month). The last month of the year was February. Thus, in the leap year of the days there were 366, with an additional 24 hours in the last month.

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 extra day before the calendars of the month of March. Thus, in February there were two twenty-fourth numbers. Leap years were appointed in three years, and the first of them happened already during the lifetime of Caesar Gaius Julius. After his death, the system got a little lost, because the priests made a mistake in the calculations, but in due course the correct calendar of leap years was restored.

Now leap years are considered a little more complicated. And this is due to the few extra minutes that are obtained by introducing a full additional day every four years.

New Calendar

The Gregorian calendar, according to which secular society currently lives, was introduced by Pope Gregory in the late 16th century. The reason for introducing a new calendar is that the old time count was inaccurate. Adding a day every four years, the Roman ruler did not take into account that so the official calendar will be ahead of the usual for 11 minutes and 46 seconds every four years.

At the time of the introduction of the new calendar, the inaccuracy of the Julian was at 10 days, with the passage of time it increased and is now 14 days. The difference increases every century for about a day. It is especially noticeable on the day of the summer and winter solstice. And since some holidays are counted from these dates, the difference was noticed.

The calendar of leap years according to the Gregorian reckoning is slightly more complicated than in the Julian calendar.

Structure of the Gregorian calendar

The Gregorian calendar takes into account the difference in the official and astronomical calendar at 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 one is not? Is there a system and algorithm in canceling an extra day? Or is it better to use a leap years list?

For convenience, such an algorithm is actually introduced. In general, every fourth year is considered a leap year, for convenience, years that are multiples of four are used. Therefore, if it is necessary to know whether the year of birth of the grandmother or the outbreak of World War II was a leap year, you just need to find out whether this year is divided by 4 or not. Thus, 1904 is a leap year, 1908 is also, and 1917 is not.

A leap year is canceled when the centuries change, that is, in a year that is a multiple of 100. Thus, 1900 was not a leap year, because it is a multiple of 100, non-leap years are also the 1800th and 1700th. But the extra day is not running for a century, but for about 123 years, that is, again it is necessary to make amendments. How can we understand which year is a leap year? If the year is a multiple of 100 and a multiple of 400, it is considered a leap year. That is, 2000 was a leap year, as well as the 1600th.

The Gregorian calendar with such complex amendments is so accurate that there is too much time left, but it's about seconds. Such seconds are also called leap ones, so that you can immediately understand what you are talking about. There are two of them each year and they are added on June 30 and December 31 at 23:59:59. These two seconds equalize astronomical and universal time.

What is the difference between a leap year?

A leap year is longer than usual for one day, there are 366 days in it. Earlier, back in Roman times, this year there were two days on February 24, but now, of course, dates are considered differently. This year in February for one day more than usual, that is 29.

But it is believed that the year in which there are February 29, unhappy. There is a belief that in leap years the death rate rises, there are various misfortunes.

Happy or unhappy?

If you look at the death rate diagram 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, a low standard of living and other problems. Yes, the two-thousandth was leap (since it is divided by 400), but is this the rule? 1996 is by no means the record for mortality, in the preceding year 1995, the death rate was higher.

In almost a half-century, this indicator reached a minimum in 1987. The year is not a leap year, but in 1986 mortality was also low, much lower than, for example, in 1981.

There are many more examples, but it is already clear that mortality in "long" years does not increase.

If you look at the statistics of fertility, then a clear relationship with the length of the year, too, can not be found. Leap years of the 20th century did not confirm the theory of misfortunes. The birth rate both in Russia and in European countries is evenly falling. A small rise is observed only in 1987, and then the birth rate begins to grow stably after 2008.

Maybe a leap year determines some tension in politics or predetermines natural disasters or wars?

Among the dates of the outbreak of hostilities, you can find only one leap year: the 1812th - the war with Napoleon. For Russia, it ended quite happily, but, of course, in itself was a serious test. But neither the year of the 1905 revolution nor 1917 were leap years. The year of the beginning of the Second World War (1939) was certainly the most unfortunate year for the whole of Europe, but it was not a leap year.

In leap years, there were earthquakes in Armenia and a hydrogen bomb explosion, but events such as the Chernobyl disaster, the tragedy in the Japanese cities of Hiroshima and Nagasaki, volcanic eruptions and other disasters occurred in the most ordinary years. The list of leap years in the 20th century does not at all coincide with a mournful list of misfortunes and disasters.

Causes of misfortunes

Psychologists believe that all statements about the leap-year of leap year are nothing more than superstition. If it is confirmed, they say so. And if not confirmed, this is simply forgotten. But the expectation of misfortunes in itself can be distressing and "pulling". It is not for nothing that often something happens to a person that he is afraid of.

One of the saints said: "If you do not believe in signs, they will not be fulfilled." In this case, this is just the way.

Leap Year in Hebrew

The traditional Jewish calendar uses the lunar months, which last 28 days. As a result, the calendar year for this system lags behind the astronomical for 11 days. For the adjustment, an additional month is regularly introduced in the year. The leap year in the traditional Jewish calendar consists of thirteen months.

A leap year for Jews is more common: from nineteen years only twelve are common, and seven more are leap years. That is, leap years for Jews are much more than in the ordinary case. But the speech, of course, is only about the traditional Jewish calendar, not about the way the modern state of Israel lives.

A leap year: when the next

All our contemporaries will no longer face exceptions in the leap years count. 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 divided by 4.

2012 was a leap year, 2016 will also be, the 2020 and 2024th, 2028th and 2032th will become leap years. It is quite easy to calculate. Know this, of course, necessary, but do not let this information scare. And in a leap year, there are wonderful and joyful events. For example, people born on February 29 are considered lucky and happy.