We are now living according to the Gregorian calendar. In our country, it was introduced by the Decree of the Council of People's Commissars of January 24, 1918. The decree said that the new calendar was introduced into civilian use with the aim of "establishing in Russia the same time calculation with almost all cultural peoples."
Julian and Gregorian calendars
Before the transition to the Gregorian calendar, which occurred at different times in different countries, the Julian calendar was widely used. It was named so in honor of the Roman emperor Gaius Julius Caesar, who, it is believed, carried out a calendar reform in 46 BC.
The Julian calendar appears to be based on the Egyptian solar calendar. The Julian year was 365.25 days. But there can be only a whole number of days in a year. Therefore, it was supposed: to consider three years equal to 365 days, and the fourth year following them equal to 366 days. This year with an extra day was called a leap year.
In 1582, Pope Gregory XIII issued a bull ordering "to return the vernal equinox to March 21st." It had by that time gone from the designated date by ten days, which were removed from that year 1582. And so that the error did not accumulate in the future, it was prescribed to throw out three days out of every 400 years. Years are not leap years, the numbers of which are multiples of 100, but not multiples of 400.
The pope threatened to excommunicate anyone who did not switch to the Gregorian calendar. Almost immediately Catholic countries switched over to it. After some time, Protestant states followed their example. In Orthodox Russia and Greece, the Julian calendar was adhered to until the first half of the 20th century.
Which calendar is more accurate
The debate about which of the calendars - the Gregorian or Julian, more precisely, does not subside to this day. On the one hand, the year of the Gregorian calendar is closer to the so-called tropical year - the interval during which the Earth makes a complete revolution around the Sun. According to modern data, the tropical year is 365.2422 days. On the other hand, scientists still use the Julian calendar for astronomical calculations.
The purpose of the calendar reform of Gregory XIII was not to bring the length of the calendar year closer to the size of the tropical year. In his time, there was no such thing as a tropical year. The purpose of the reform was to comply with the decisions of the ancient Christian councils on the timing of the celebration of Easter. However, he did not completely solve the task.
The widespread belief that the Gregorian calendar is "more correct" and "more advanced" than the Julian calendar is just a propaganda cliche. The Gregorian calendar, according to a number of scientists, is astronomically unjustified and is a distortion of the Julian calendar.
