Have you ever wondered why all months have 31 or 30 days and only February is “deprived”, having received only 28 days? What is so remarkable about this winter month? And why does an “extra” day appear once every four years? To understand and answer these questions, you need to turn to history.

Natural units of time

The first unit of time was the day. Even ancient man could determine the beginning and end of light and dark time. It was the alternation of days and nights that led to the concept of day. Therefore, it is not surprising that the solar day became the main unit of time measurement. This is the time it takes for the Earth to make a full rotation around its axis relative to the Sun, or, in other words: the time interval from noon of one day to noon of the next.

In the same way, the year was easily determined - this is a regular change of seasons. Later, with the development of astronomy, this change was associated with the rotation of the Earth around the Sun. The concept came that the full revolution of the Earth around the Sun is another natural unit of time: the annual cycle.

However, a day is too short an interval of time, and a year is too long. There was a need to introduce intermediate portions of time.

When did the months appear

The division of years into months is quite random and the root cause may be lunar cycles and based on this lunar calendars common in southern countries where there were no pronounced seasonal changes.

Initially, in the ancient Roman state, the annual cycle consisted of 304 days, divided into 10 months, and it began in March. The Romans borrowed this system from the ancient Greeks.

For 700 years BC. e. second king ancient rome Numa Pompilius carried out a reform using the knowledge of the Etruscans: their calendar contained 12 months. He brought the duration of the annual cycle to 365 days and added the last two months: January and February. In this calendar, all months had an odd number of days (even numbers were considered unlucky) and contained 31 or 29 days, except for the very last month of the year - February. It had only 28 days - as much as left after the "distribution" to other months.

It remains to find out where the 29th day in February comes from.

chronology

But first you need to determine exactly how many days is one annual cycle.

The daily rotation of the Earth around its axis and the annual rotation around the Sun are independent processes, and it would be incredible if the period of a full circle consisted of exactly an integer number of days.

If the duration of the usual cycle of the year is determined as 365 days, then after each revolution of the Earth around the Sun, an extra 6 hours remain, and in 4 years 24 hours will accumulate, that is, a whole day.

They are added to February as the 29th day every four years. Such a year is called a leap year, and it is also an Olympic year. His hallmark: The year number is divisible by four.

Julian calendar

A calendar built in this way is called a Julian calendar. He was approved in 45 BC. e. Julius Caesar. In doing so, the knowledge and observations accumulated in Ancient Egypt over the millennia of its civilization.

Caesar moved the beginning of the annual calculation to January 1, when new consuls took office in Rome. An attempt was made to roughly equalize the number of days in months, but when, under the emperor Octavian Augustus, one day was taken from February to add to the namesake of the emperor - the month of August, the usual (non-leap) February irrevocably became a 28-day month.

Gregorian calendar

The Earth makes a complete revolution around the Sun in 365.24222 days. in the julian calendar average duration of the annual cycle is taken equal to 365.25 days, which is more than the true value.

This time, accumulated with each revolution of the Earth around the Sun, will turn into a whole day in 128 years. Millennia from now, Christmas will be in the summer, and Easter will have to be celebrated in the fall.

The church, preoccupied with this problem, has long tried to reform the calendar, but only in 1582 this improved version was legalized in Catholic countries by the decision of Pope Gregory XIII, and then spread throughout the world.

The changes made to the Julian calendar were simple and painless. The average duration of the annual cycle was determined to be 365.2425 days, which is much closer to the true value.

From this follows a simple way of constructing the Gregorian calendar. To obtain such an average annual time interval averaged over 400 years, it is necessary to regulate the duration of February by adding the 29th day or, conversely, subtracting it.

One of the shortest months in the current calendar was and remains February. It accounts for only 28 days. Only once every four years, he gets another 1 day, which often does not please anyone except birthdays.

And he was born the latest of all known months. Why did it happen, and who came up with such injustice?

Calendar history

The modern world lives on Gregorian calendar. It is received as a gift from the ancient Roman and Julian. Despite the near-world dominance of Rome, the chronology of those days was a complete mess. So, three thousand years ago, the year began in March, when they started sowing agricultural work. The cycle consisted of 304 days, divided into 10 months.

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The years were not accounted for in order. Each of them was called the name of the ruler who sat on the throne. And in settlements days were counted differently. For example, in one region October could be 32 days, and in another - it did not reach 25 or exceeded 39. The only thing that this mighty people adhered to was the frequency of alternating odd months with even ones.

The latter were not honored. People tried not to make grandiose plans for even months, considering them less successful for global events. AND for a long time emperors did not think that the calendar year did not correspond at all to the actual lunar and solar cycles.

The appearance of January and February

King Numo was the first to pay attention to this. This discrepancy confused him. He decided to reform. To restore the correspondence, it was necessary to add two whole months to the end of the year. This is how January and February appeared for humanity. On the last it turned out to allocate 28 days. Its name translates as "cleansing". Since he completed the year with himself, he was dedicated to rituals associated with long-dead ancestors.

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This innovation did not completely reduce the difference. Indeed, in a year there is not an integer number of days (365), but together with hours. Ticking, they gradually move the calendar cycle away from the actual one. At some point, the gap reached 90 days. Again, something had to be done.

The appearance of a leap year in the calendar


The perspicacious Julius Caesar commissioned this difficult task famous astronomer Sosigenes. Through mathematical calculations, the scientist came to the conclusion that it is necessary to add 1 more day every 4 years, accumulated by extra hours. And it was decided to give it to February. This is how the concept of "leap year" ("annus bissextus") appeared. Translated, this expression means "twice the sixth." The origin of the term follows from the peculiarities of counting days in the Roman way. The month was divided into three decades. The first was called "calenda" (hence the word "calendar").

February is the most short month in a year, in leap years it has 29 days, and in other years - 28. AiF.ru figured out why this happened.

Roman heritage

The calendar by which we live came to us from Ancient Rome. Initially, it had ten months, and the year began in March. King Numa in the 8th century BC. I decided to put the calendar in order so that it would be more in line with the phases of the moon and the movement of the sun. As a result of the reform, two additional months were introduced - January and February.

During the reign Julius Caesar it was established that even months should last 30 days, and odd - 31. February, which then fell at the end of the year, required amount didn't get a day. As a result, this winter month received only 29 days at its disposal. In 44 BC. e. the popular ruler dies, and the new Roman administration decides to rename the month of July Quintilis in his honor. Subsequently, who died in 14 BC. e. Emperor Octavian Augustus also honored with a nominal month. Since August and July followed each other, in those days there were different amount days. Officials for political reasons decided to equalize the merits of both rulers up to 31 days. This approach required borrowing an extra day from another month. A strong-willed decision to "pin off" the day was decided in February. The choice was explained, most likely, by the fact that this month had a bad reputation among the Romans, since it was at this time of the year that it was customary to commemorate the dead.

Why does February have 28 or 29 days?

system leap years, in which not 365, but 366 days, was also introduced by Julius Caesar. This was done so that the calendar year would correspond to the period of rotation of the Earth around the Sun, which is 365.25 days (365 days and 6 hours). To do this, it is necessary to increase the number of days in the calendar by one every four years. The choice for ease of remembering again fell on February, since at that time it was last month in a year.

Photo: Shutterstock.com

Have you tried to increase the number of days in February?

Yes, they tried. In 1930, the possibility of introducing a revolutionary Soviet calendar that included February 30 was discussed in the USSR, but the proposal was not accepted.

signs of february

In February, severe frosts - a short winter.

Long February icicles promise a long winter.

February is cold and dry - August is hot.

Warm February brings cold spring.

In February, there is a lot of frost on the trees - there will be a lot of honey.

If February is rainy, then spring and summer can be expected the same, and if it is weathery, then this portends a drought.

The beginning of February is more serene - and expect an early spring, more beautiful.

The colder the last week February, the warmer in March.

Responsible for the head of the department of meteorology

and Climatology SSU, Doctor of Physics and Mathematics

Science Mikhail Bogdanov:

February is the most unusual month of the year. It appeared on the calendar later than others, and the number of days in it has changed more than once. Initially, the ancient Roman calendar year began on March 1, was divided into ten months and lasted only 304 days. Around 690 B.C. e. The ruler of ancient Rome, Numa Pompilius, added January and February to the calendar. February was dedicated to the god of the underworld, Februus, and its name comes from the Latin word februare - "to purify". It became the last month of the year, so it had only 28 days.

In 46 BC. e. Julius Caesar carried out another calendar reform. The basis julian calendar A tropical year of 365.2422 days was established. But the calendar year must contain an integer number of days, so a cycle of four years was introduced: three simple years for 365 days, and the fourth, leap year, - 366. At the same time, the average duration calendar year 365.25 days is close enough to a tropical year. Julius Caesar also ordered the number of days in months according to this principle: odd - 31 days, even - 30. February in a normal year was supposed to have 29, and in a leap year - 30 days. New calendar began to operate on January 1, 45 BC. e., but a year later Julius Caesar died, and an unfortunate mistake crept into the calendar - the Roman priests declared leap years not every fourth, but every third year. The situation was corrected by Emperor Augustus. In gratitude for this, the Roman Senate in 8 BC. e. renamed the month sextilis to augustus. But it had 30 days, and the ancient Romans believed that even numbers bring bad luck. Therefore, another day was added to August, taking it away from February. Since then, February has 28 days in common years and 29 in leap years.