Since 46 BC, most countries in the world have used the Julian calendar. However, in 1582, by the decision of Pope Gregory XIII, it was replaced by Gregorian. That year, the next day after the fourth of October was not the fifth, but the fifteenth of October. Now the Gregorian calendar is officially adopted in all countries except Thailand and Ethiopia.

Reasons for adopting the Gregorian calendar

The main reason for introducing new system chronology became the movement of the day spring equinox, depending on which the date of celebration of Christian Easter was determined. Due to discrepancies between the Julian and tropical calendars (the tropical year is the period of time during which the sun completes one cycle of changing seasons), the day of the vernal equinox gradually shifted to earlier dates. At the time of the introduction of the Julian calendar, it fell on March 21, both according to the accepted calendar system and in fact. But by the 16th century, the difference between the tropical and Julian calendars was already about ten days. As a result, the vernal equinox no longer fell on March 21, but on March 11.

Scientists paid attention to the above problem long before the adoption of the Gregorian chronology system. Back in the 14th century, Nikephoros Grigora, a scientist from Byzantium, reported this to Emperor Andronicus II. According to Grigora, it was necessary to revise the calendar system that existed at that time, since otherwise the date of Easter would continue to shift to a later and later time. However, the emperor did not take any action to eliminate this problem, fearing protest from the church.

Subsequently, other scientists from Byzantium also spoke about the need to switch to a new calendar system. But the calendar continued to remain unchanged. And not only because of the rulers’ fear of causing indignation among the clergy, but also because the further the Christian Easter moved away, the less chance it had of coinciding with the Jewish Passover. This was unacceptable according to church canons.

By the 16th century, the problem had become so urgent that the need to solve it was no longer in doubt. As a result, dad Gregory XIII assembled a commission that was tasked with carrying out all the necessary research and creating a new calendar system. The results obtained were displayed in the bullet “Among the most important”. It was she who became the document with which the adoption of the new calendar system began.

The main disadvantage of the Julian calendar is its lack of accuracy in relation to the tropical calendar. In the Julian calendar, all years that are divisible by 100 without a remainder are considered leap years. As a result, the difference with the tropical calendar increases every year. Approximately every century and a half it increases by 1 day.

The Gregorian calendar is much more accurate. It has fewer leap years. In this chronology system, leap years are considered to be years that:

1. divisible by 400 without remainder;
2. divisible by 4 without a remainder, but not divisible by 100 without a remainder.

Thus, 1100 or 1700 years in the Julian calendar are considered leap years, since they are divisible by 4 without a remainder. In the Gregorian calendar, from those that have already passed since its adoption, 1600 and 2000 are considered leap years.

Immediately after the introduction of the new system, it was possible to eliminate the difference between the tropical and calendar years, which at that time was already 10 days. Otherwise, due to errors in calculations extra year would run every 128 years. In the Gregorian calendar, an extra day occurs only every 10,000 years.

Not all modern states adopted the new chronology system immediately. The Catholic states were the first to switch to it. In these countries, the Gregorian calendar was officially adopted either in 1582 or shortly after the decree of Pope Gregory XIII.

In a number of states, the transition to a new calendar system was associated with popular unrest. The most serious of them took place in Riga. They lasted for five whole years - from 1584 to 1589.

There were also some funny situations. So, for example, in Holland and Belgium, due to the official adoption of the new calendar, after December 21, 1582, January 1, 1583 came. As a result, the inhabitants of these countries were left without Christmas in 1582.

Russia was one of the last to adopt the Gregorian calendar. The new system was officially introduced on the territory of the RSFSR on January 26, 1918 by decree of the Council of People's Commissars. In accordance with this document, immediately after January 31 of that year, February 14 came on the territory of the state.

Later than in Russia, the Gregorian calendar was introduced only in a few countries, including Greece, Turkey and China.

After the official adoption of the new chronology system, Pope Gregory XIII sent a proposal to Constantinople to switch to a new calendar. However, she was met with refusal. Its main reason was the inconsistency of the calendar with the canons of celebrating Easter. However, later most Orthodox churches switched to the Gregorian calendar.

Today, only four Orthodox churches use the Julian calendar: Russian, Serbian, Georgian and Jerusalem.

Rules for specifying dates

In accordance with the generally accepted rule, dates falling between 1582 and the moment the Gregorian calendar was adopted in the country are indicated in both the old and new styles. In this case, the new style is indicated in quotation marks. Earlier dates are indicated according to the proleptic calendar (i.e., a calendar used to indicate dates earlier than the date the calendar appeared). In countries where the Julian calendar was adopted, dates before 46 BC. e. are indicated according to the proleptic Julian calendar, and where there was none - according to the proleptic Gregorian calendar.

Gregorian calendar

The Gregory calendar in Catholic countries was introduced by Pope Gregory XIII on October 4, 1582 to replace the old Julian calendar: the next day after Thursday, October 4, became Friday, October 15.

In the Gregorian calendar, the length of the year is taken to be 365.2425 days. The duration of a non-leap year is 365 days, a leap year is 366.

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

This follows the distribution of leap years:

A year whose number is a multiple of 400 is a leap year;

The remaining years - the year whose number is a multiple of 100 - is not a leap year;

The remaining years are a year whose number is a multiple of 4 - a leap year.

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 that leads to a value of the order of 3000 years, obtained by comparing the length of the year in the Gregorian calendar with the average current astronomical length of the tropical year, is associated with the incorrect definition of the latter as the interval between adjacent equinoxes and is a well-established misconception.

Months

According to the Gregorian calendar, the year is divided into 12 months, lasting from 28 to 31 days:

Story

The reason for the adoption of the new calendar was the gradual shift in relation to the Julian calendar of the day of the vernal equinox, by which the date of Easter was determined, and the discrepancy between the Easter full moons and the astronomical ones. Before Gregory XIII, Popes Paul III and Pius IV tried to implement the project, but they did not achieve success. The preparation of the reform, at the direction of Gregory XIII, was carried out by astronomers Christopher Clavius ​​and Luigi Lilio (aka Aloysius Lilius). The results of their work were recorded in a papal bull, named after the first line of the Latin. Inter gravity(“Among the most important”).

Firstly, the new calendar immediately at the time of adoption shifted the current date by 10 days due to accumulated errors.

Secondly, a new, more precise rule about leap years began to apply. A year is a leap year, that is, it contains 366 days if:

1. year number is a multiple of 400 (1600, 2000, 2400);

2. other years - the year number is a multiple of 4 and not a multiple of 100 (...1892, 1896, 1904, 1908...).

Thirdly, the rules for calculating Christian Easter were modified.

Thus, over time, the Julian and Gregorian calendars diverge more and more: by 1 day per century, if the number of the previous century is not divisible by 4. The Gregorian calendar is much more accurate than the Julian calendar. It gives a much better approximation of the tropical year.

In 1583, Gregory XIII sent an embassy to Patriarch Jeremiah II of Constantinople with a proposal to switch to a new calendar. At the end of 1583, at a council in Constantinople, the proposal was rejected as not complying with the canonical rules for celebrating Easter.

In Russia, the Gregorian calendar was introduced in 1918 by a decree of the Council of People's Commissars, according to which in 1918 January 31 was followed by February 14.

Since 1923, most local Orthodox churches, with the exception of the Russian, Jerusalem, Georgian, Serbian and Athos, have adopted the New Julian calendar, similar to the Gregorian, which coincides with it until the year 2800. It was also formally introduced by Patriarch Tikhon for use in Russian Orthodox Church October 15, 1923. However, this innovation, although it was accepted by almost all Moscow parishes, generally caused disagreement in the Church, so already on November 8, 1923, Patriarch Tikhon ordered “the universal and mandatory introduction of the new style into church use to be temporarily postponed.” Thus, the new style was in effect in the Russian Orthodox Church for only 24 days.

In 1948, at the Moscow Conference of Orthodox Churches, it was decided that Easter, like all moving holidays, should be calculated according to the Alexandrian Paschal (Julian calendar), and non-transitionable ones according to the calendar by which one lives Local Church. The Finnish Orthodox Church celebrates Easter according to the Gregorian calendar.

Difference between Julian and Gregorian calendars

Difference between Julian and Gregorian calendar dates:

Until October 5 (15), 1582, there was only one calendar - the Julian. You can recalculate retroactively according to the table. For example, July 14 (23), 1471.

Dates of countries switching to the Gregorian calendar

Notes

From this list it follows that in a number of countries, for example in Russia, there was a day on February 29 in 1900, while in most countries it was not.

In some countries that switched to the Gregorian calendar, the Julian calendar was subsequently resumed as a result of their annexation with other states.

In the 16th century, only the Catholic part of Switzerland switched to the Gregorian calendar; the Protestant cantons switched in 1753, and the last, Grisons, in 1811.

In a number of cases, the transition to the Gregorian calendar was accompanied by serious unrest. For example, when the Polish king Stefan Batory introduced a new calendar in Riga (1584), local merchants rebelled, claiming that a 10-day shift would disrupt their delivery times and lead to significant losses. The rebels destroyed the Riga church and killed several municipal employees. It was possible to cope with the “calendar unrest” and hang its leaders only in the summer of 1589.

Due to the transition of countries to the Gregorian calendar at different times, factual errors of perception may arise: for example, it is known that Miguel de Cervantes and William Shakespeare died on April 23, 1616. In fact, these events occurred 10 days apart, since in Catholic Spain the new style was in effect from the very introduction of it by the pope, and Great Britain switched to the new calendar only in 1752.

The change to the Gregorian calendar in Alaska was unusual because it was combined with a change in the date line. Therefore, after Friday October 5, 1867, according to the old style, there was another Friday, October 18, 1867, according to the new style.

The Gregorian calendar is the most widely used chronological system today, named after the XII, who insisted on its introduction in the Catholic world. Many people mistakenly believe that it was Gregory who came up with this system, however, this is far from the case. According to one version, the main inspirer of this idea was the Italian doctor Aloysius, who theoretically substantiated the need to change the chronology that existed before.

The problem of chronology has always been quite acute, because the development of historical science in the country, and even the worldview of ordinary citizens, largely depends on what is taken as the starting point and what a day, month and year are equal to.

There were and are many chronological systems: some take as a basis the movement of the moon around the Earth, others consider the creation of the world to be the starting point, and others consider the departure of Muhammad from Mecca. In many civilizations, each change of ruler led to a change in the calendar. Moreover, one of the main difficulties is that neither an earthly day nor an earthly year lasts for a round number of hours and days; the whole question is - what to do with the remaining balance?

One of the first most successful systems was the so-called one, named after the reign of which it appeared. The main innovation was that one day was added to every fourth year. This year began to be called a leap year.

However, the introduction only temporarily alleviated the problem. On the one hand, the discrepancy between the calendar year and the tropical year continued to accumulate, although not at such a rapid pace as before, and on the other hand, Easter Day fell on different days weeks, although, according to most Catholics, Easter should always fall on Sunday.

In 1582, after numerous calculations and based on clear astronomical calculations, in Western Europe There was a transition to the Gregorian calendar. This year in many European countries immediately after October 4th came the fifteenth.

The Gregorian calendar largely repeats the main provisions of its predecessor: a regular year also consists of 365 days, and a leap year - of 366, and the number of days changes only in February - 28 or 29. The main difference is that the Gregorian calendar excludes all leap years years divisible by one hundred, except those divisible by 400. In addition, if according to the Julian calendar New Year occurred on the first of September or the first of March, then in the new chronological system it was initially declared on December 1, and then shifted another month.

In Russia, under the influence of the church, the new calendar was not recognized for a long time, believing that according to it the entire sequence of evangelical events was disrupted. The Gregorian calendar was introduced in Russia only at the beginning of 1918, when the fourteenth day arrived immediately after the first of February.

Despite its much greater accuracy, the Gregorian system is still imperfect. However, if in the Julian calendar an extra day was formed in 128 years, then in the Gregorian calendar this would require 3200.

For all of us, the calendar is a familiar and even mundane thing. This ancient invention of man records days, dates, months, seasons, periodicity natural phenomena, which are based on the system of movement of celestial bodies: the Moon, the Sun, the stars. The earth rushes by solar orbit, leaving years and centuries behind.
In one day, the Earth makes one complete revolution around its own axis. It passes around the Sun once per year. The solar or astronomical year lasts three hundred sixty-five days, five hours, forty-eight minutes, forty-six seconds. Therefore, there is no integer number of days. Hence the difficulty in drawing up an accurate calendar for the correct counting of time.
The ancient Romans and Greeks used a convenient and simple calendar. The rebirth of the Moon occurs at intervals of 30 days, or to be precise, at twenty-nine days, twelve hours and 44 minutes. That is why days and then months could be counted by changes in the Moon. In the beginning, this calendar had ten months, which were named after the Roman gods. From the third century BC to ancient world an analogue was used based on the four-year lunar-solar cycle, which gave an error in the value of the solar year of one day. In Egypt they used a solar calendar based on observations of the Sun and Sirius. The year according to it was three hundred sixty-five days. It consisted of twelve months of thirty days. After it expired, another five days were added. This was formulated as “in honor of the birth of the gods.”

History of the Julian Calendar Further changes occurred in the forty-sixth year BC. e. The Emperor of Ancient Rome, Julius Caesar, introduced the Julian calendar based on the Egyptian model. In it, the value of the year was taken solar year, which was slightly larger than the astronomical one and amounted to three hundred sixty-five days and six hours. The first of January marked the beginning of the year. According to the Julian calendar, Christmas began to be celebrated on January 7th. This is how the transition to a new calendar took place. In gratitude for the reform, the Senate of Rome renamed the month of Quintilis, when Caesar was born, to Julius (now July). A year later, the emperor was killed, and the Roman priests, either out of ignorance or deliberately, again began to confuse the calendar and began to declare every third year a leap year. As a result, from forty-four to nine BC. e. Instead of nine, twelve leap years were declared. Emperor Octivian Augustus saved the situation. By his order, there were no leap years for the next sixteen years, and the rhythm of the calendar was restored. In his honor, the month Sextilis was renamed Augustus (August).

For the Orthodox Church, simultaneity was very important church holidays. The date of Easter was discussed at the First Ecumenical Council, and this issue became one of the main ones. The rules for the exact calculation of this celebration established at this Council cannot be changed under pain of anathema. Gregorian calendar The head of the Catholic Church, Pope Gregory the Thirteenth, approved and introduced a new calendar in 1582. It was called "Gregorian". It would seem that everyone was happy with the Julian calendar, according to which Europe lived for more than sixteen centuries. However, Gregory the Thirteenth considered that reform was necessary to determine more exact date celebration of Easter, and also so that the day of the vernal equinox returns again to the twenty-first of March.

In 1583, the Council of Eastern Patriarchs in Constantinople condemned the adoption of the Gregorian calendar as violating the liturgical cycle and calling into question the canons Ecumenical Councils. Indeed, in some years he breaks the basic rule of celebrating Easter. It happens that Catholic Bright Sunday falls earlier than Jewish Easter, and this is not allowed by the canons of the church. Calculation in Rus' On the territory of our country, starting from the tenth century, the New Year was celebrated on the first of March. Five centuries later, in 1492, in Russia the beginning of the year was moved, according to church traditions, to the first of September. This went on for more than two hundred years. On the nineteenth of December, seven thousand two hundred and eight, Tsar Peter the Great issued a decree that the Julian calendar in Russia, adopted from Byzantium along with baptism, was still in force. The start date of the year has changed. It was officially approved in the country. The New Year according to the Julian calendar was to be celebrated on the first of January “from the Nativity of Christ.”
After the revolution of February fourteenth, one thousand nine hundred and eighteen, new rules were introduced in our country. The Gregorian calendar excluded three leap years within each quadrant. This is what they began to adhere to. How are the Julian and Gregorian calendars different? The difference between is in the calculation of leap years. Over time it increases. If in the sixteenth century it was ten days, then in the seventeenth it increased to eleven, in the eighteenth century it was already equal to twelve days, thirteen in the twentieth and twenty-first centuries, and by the twenty-second century this figure will reach fourteen days.
The Orthodox Church of Russia uses the Julian calendar, following the decisions of the Ecumenical Councils, and Catholics use the Gregorian calendar. You can often hear the question of why the whole world celebrates Christmas on the twenty-fifth of December, and we celebrate the seventh of January. The answer is completely obvious. The Russian Orthodox Church celebrates Christmas according to the Julian calendar. This also applies to other major church holidays. Today the Julian calendar in Russia is called the “old style”. Currently, its scope of application is very limited. It is used by some Orthodox Churches - Serbian, Georgian, Jerusalem and Russian. In addition, the Julian calendar is used in some Orthodox monasteries in Europe and the USA.

Gregorian calendar in Russia
In our country, the issue of calendar reform has been raised more than once. In 1830 it was staged Russian Academy Sci. Prince K.A. Lieven, who served as Minister of Education at the time, considered this proposal untimely. Only after the revolution the issue was brought to a meeting of the Council of People's Commissars Russian Federation. Already on January 24, Russia adopted the Gregorian calendar. Peculiarities of the transition to the Gregorian calendar For Orthodox Christians, the introduction of a new style by the authorities caused certain difficulties. The New Year turned out to be shifted to the Nativity Fast, when any fun is not welcome. Moreover, January 1 is the day of remembrance of St. Boniface, the patron saint of everyone who wants to give up drunkenness, and our country celebrates this day with a glass in hand. Gregorian and Julian calendar: differences and similarities Both of them consist of three hundred sixty-five days in a normal year and three hundred sixty-six in a leap year, have 12 months, 4 of which are 30 days and 7 are 31 days, February is either 28 or 29 The only difference is the frequency of leap years. According to the Julian calendar leap year occurs every three years. In this case it turns out that calendar year longer than astronomical by 11 minutes. In other words, after 128 years there is an extra day. The Gregorian calendar also recognizes that the fourth year is a leap year. The exceptions are those years that are multiples of 100, as well as those that can be divided by 400. Based on this, extra days appear only after 3200 years. What awaits us in the future Unlike the Gregorian calendar, the Julian calendar is simpler for chronology, but it is ahead of the astronomical year. The basis of the first became the second. According to the Orthodox Church, the Gregorian calendar violates the order of many biblical events. Due to the fact that the Julian and Gregorian calendars increase the difference in dates over time, Orthodox churches that use the first of them will celebrate Christmas from 2101 not on January 7, as is now the case, but on the eighth of January, but from nine thousand In the year nine hundred and one, the celebration will take place on March 8th. In the liturgical calendar, the date will still correspond to the twenty-fifth of December.

In countries where the Julian calendar was used by the beginning of the twentieth century, for example in Greece, the dates of all historical events that occurred after the fifteenth of October one thousand five hundred and eighty-two are nominally celebrated on the same dates on which they occurred. Consequences of calendar reforms Currently, the Gregorian calendar is quite accurate. According to many experts, it does not need changes, but the issue of its reform has been discussed for several decades. This is not about introducing a new calendar or any new methods for accounting for leap years. It's about about rearranging the days of the year so that the beginning of each year falls on one day, for example on Sunday. Today calendar months last from 28 to 31 days, the length of the quarter ranges from ninety to ninety-two days, with the first half of the year being 3-4 days shorter than the second. This complicates the work of financial and planning authorities. What New Calendar Projects Are There Various designs have been proposed over the past one hundred and sixty years. In 1923, a calendar reform committee was created at the League of Nations. After the end of the Second World War this question was transferred to the Economic and Social Committee of the United Nations. Despite the fact that there are quite a lot of them, preference is given to two options - the 13-month calendar of the French philosopher Auguste Comte and the proposal of the French astronomer G. Armelin.
In the first option, the month always begins on Sunday and ends on Saturday. One day in the year has no name at all and is inserted at the end of the last thirteenth month. In a leap year, such a day appears in the sixth month. According to experts, this calendar has many significant shortcomings, so more attention is paid to the project of Gustave Armelin, according to which the year consists of twelve months and four quarters of ninety-one days. The first month of a quarter has thirty-one days, the next two have thirty. The first day of each year and quarter begins on Sunday and ends on Saturday. In a normal year, one additional day is added after the thirtieth of December, and in a leap year - after the 30th of June. This project was approved by France, India, Soviet Union, Yugoslavia and some other countries. For a long time The General Assembly delayed approval of the project, and in Lately this work at the UN ceased. Will Russia return to the “old style”? It is quite difficult for foreigners to explain what the concept of “Old New Year” means, why we celebrate Christmas later than Europeans. Today there are people who want to make the transition to the Julian calendar in Russia. Moreover, the initiative comes from well-deserved and respected people. In their opinion, 70% of Russian Orthodox Russians have the right to live according to the calendar used by the Russian Orthodox Church. http://vk.cc/3Wus9M

Christmas is the most fabulous, the most magical holiday. A holiday that promises a miracle. The most long-awaited holiday of the year. Christmas is more important than New Year. This is how it is in the West, and this is how it was in Russia before the revolution. It is Christmas that is the warmest family celebration with the obligatory Christmas tree and the expectation of gifts from Santa Claus or Father Frost.

So why do Christians have two Christmases today? Why do Orthodox Christians celebrate Christmas on January 7, and Catholics and Protestants on December 25?

And the point here is not at all about religious differences, but just about the calendar. Initially, Europe used the Julian calendar. This calendar appeared before our era and was generally accepted until the 16th century. The Julian calendar was named after Julius Caesar, who introduced this calendar in 45 BC. to replace the outdated Roman calendar. The Julian calendar was developed by a group of Alexandrian astronomers led by Sosigenes. Sosigenes is an Alexandrian scientist, a scientist from the very same Alexandria, which was located on Egyptian lands. He was invited to Rome by Caesar to develop a calendar. He is also known for his philosophical treatises, for example, a commentary on Aristotle's treatise De Caelo. But his philosophical works have not survived to this day.

The Julian calendar was developed based on ancient Egyptian knowledge of astronomy. In the Julian calendar, the year begins on January 1, since it is on this day in Ancient Rome The newly elected consuls took office. The year consisted of 365 days and was divided into 12 months. Once every four years there was a leap year, to which one day was added - February 29. But the calendar was not accurate enough. Every 128 years, one extra day accumulated. And Christmas, which in the Middle Ages was celebrated in Western Europe almost on the days winter solstice, began to gradually move away closer and closer to spring. The day of the vernal equinox, by which the date of Easter was determined, also shifted.

And then the Popes came to the understanding that the calendar was not accurate and needed to be improved. Gregory XIII became the pope who carried out the calendar reform. It was in honor of him that the new calendar was named Gregorian. Before Gregory XIII, attempts to change the calendar were made by Popes Paul III and Pius IV, but their attempts were not successful. The new Gregorian calendar was introduced on October 4, 1582. The development of the calendar on behalf of the pope was carried out by astronomers Christopher Clavius ​​and Aloysius Lilius. After the introduction of the new calendar in 1582, the date 4 October Thursday was immediately followed by a new date - 15 October Friday. This is exactly how far behind the Gregorian calendar the Julian calendar was by that time.

The Gregorian calendar consists of 365 days per year; a leap year has 366 days. But at the same time, the calculation of leap years has become more advanced. So a leap year is a year whose number is a multiple of 4. Years divisible by 100 are leap years if they are divided by 400. Thus, 2000 was a leap year, 1600 was a leap year, and 1800 or 1900, for example, were not leap years. An error in one day now accumulates over 10,000 years, in the Julian - over 128 years.

With each century, the difference in days between the Gregorian and Julian calendars increases by exactly one day.

By 1582, initially united Christian church has already split into two parts - Orthodox and Catholic. In 1583, Pope Gregory XIII, head catholic church, sent an embassy to the head of the Orthodox Church, Patriarch of Constantinople Jeremiah II, with a proposal to also switch to the Gregorian calendar, but he refused.

So it turned out that Catholics and Protestants celebrate Christmas on December 25 according to the new Gregorian calendar, and the Orthodox - the Russian, Jerusalem, Serbian, Georgian Orthodox churches and Mount Athos - according to the old Julian calendar and also on December 25, but which, however, in the modern Gregorian calendar falls on Jan. 7.

The Constantinople, Antioch, Alexandria, Cyprus, Bulgarian, Romanian, Greek and some other Orthodox churches adopted the New Julian calendar, which is similar to the Gregorian calendar, and just like Catholics celebrate Christmas on December 25.

By the way, in the Russian Orthodox Church there were also attempts to switch to the New Julian calendar, similar to the Gregorian one. On October 15, 1923, it was introduced into the Russian Orthodox Church by Patriarch Tikhon. This innovation was accepted by Moscow parishes, but it caused disagreements within the Church itself and on November 8, 1923, by decree of Patriarch Tikhon, “it was temporarily postponed.”

IN Russian Empire Even in the 19th and early 20th centuries, chronology, unlike in Europe, was carried out according to the Julian calendar. The Gregorian calendar was introduced only after the revolution in 1918 by decree of the Council of People's Commissars. Then such names as the “old style” - the Julian calendar and the “new style” - the Gregorian calendar appeared. Christmas began to be celebrated after the New Year. And besides the New Year itself, the Old New Year also appeared, basically the same New Year, but according to the old Julian calendar.

This is the calendar story. Merry Christmas, and perhaps Christmas, and New Year, or New Years. Happy holidays to you!