The Gregorian calendar is currently the most common chronological system, named after Pope Gregory XII, who insisted on its introduction in the Catholic world. Many people mistakenly believe that it was Gregory who invented this system, however, this is far from the case. According to one version, the main inspirer of this idea was the Italian physician Aloysius, who theoretically substantiated the need to change the existing chronology.
The problem of chronology at all times was quite acute, because the development of historical science in the country, and even the worldview of ordinary citizens, largely depend on what is taken as a reference point and what the day, month and year are equal to.
Many chronological systems existed and exist: some take the movement of the moon around the Earth as the basis, others consider the creation of the world as the starting point, others as the departure of Muhammad from Mecca. In many civilizations, each change of ruler led to a change of calendar. At the same time, one of the main difficulties is that neither the earthly day, nor the 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 Julian calendar, named after Guy Julius Caesar, in whose reign he appeared. The main innovation was the fact that one day was added to every fourth year. This year began to be called a leap year.
However, the introduction of a leap year only temporarily smoothed out the problem. On the one hand, the discrepancy between the calendar year and the tropical one continued to accumulate, although not as fast as before, and on the other hand, Easter day fell on different days of the week, although, according to most Catholics, Easter should always be on Sunday.
In 1582, after numerous calculations and based on clear astronomical calculations, a transition to the Gregorian calendar occurred in Western Europe. This year, in many European countries, immediately after October 4, the fifteenth came.
The Gregorian calendar largely repeats the main provisions of its predecessor: the usual year also consists of 365 days, and the leap year consists of 366, and the number of days only changes in February - 28 or 29. The main difference is that the Gregorian calendar excludes everything from the leap year years, multiples of a hundred, with the exception of those divisible by 400. In addition, if according to the Julian calendar the New Year came on the first of September or the first of March, then in the new chronological system it was initially announced on December 1, and then shifted e ie for a month.
In Russia, under the influence of the church, the new calendar was not recognized for a long time, considering that according to it the whole sequence of evangelical events was broken. The Gregorian calendar in Russia was introduced only in early 1918 after the Bolsheviks came to power, when the fourteenth arrived immediately after the first of February.
Despite 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 it will require 3200.
