What happened from October 5 to 14, 1582? Any. they did not exist

This October 5 marks the 439th anniversary of the disappearance of the Julian calendar and the advent of the Gregorian calendar, which is still in force.

What did this change represent? Exactly, that the old chronology ended on a Thursday, October 4, and had its correlate on Friday, already declared October 15 in the new calendar. In short, ten pages of the calendar fell without further ado.

The Gregorian reform stems from the need to put into practice one of the agreements of the Council of Trent: to adjust the calendar to eliminate the gap produced since the first Council of Nicaea, held in 325, in which the astral moment had been set at that Easter should be celebrated and, in connection with it, the other mobile religious festivals. What mattered, then, was the regularity of the liturgical calendar, for which it was necessary to introduce certain corrections in the civil calendar. Basically, it was about adapting the civil calendar to the tropical year.

At the Council of Nicaea it was determined that Easter should be commemorated on the Sunday following the full moon after the spring equinox in the northern hemisphere (autumnal equinox in the southern hemisphere). That year 325 the equinox had occurred on March 21, but over time the date of the event had been brought forward to the point that in 1582, the gap was already 10 days, and the equinox was dated on 11 of March.

The gap came from an inaccurate calculation of the number of days in the tropical year; According to the Julian calendar that instituted a leap year every four, he considered that the tropical year was made up of 365.25 days, while the correct figure is 365.242189, or what is the same, 365 days, 5 hours, 48 minutes and 45.16 seconds. Those more than 11 minutes counted in addition to each year had meant an accumulated error of approximately 10 days in the 1,257 years between 325 and 1582, according to Wikipedia.

The Gregorian calendar –fundamentally promoted by the German Jesuit Christopher Clavius– adjusts this gap by changing the general rule of the leap year every four years, and exempts years that are multiples of 100, an exception that in turn had another exception, that of years that are multiples of 400, which were leap years.

The new rule for leap years was formulated as follows: the basic length of the year is 365 days; but they will be leap years (that is, they will have 366 days) those years whose last two figures are divisible by 4, except for the multiples of 100 (1700, 1800, 1900…, which will not be leap years), from which they are in turn excepted those that are also divisible by 400 (1600, 2000, 2400…, which will be leap years). This system is still in force today. Thus, the year 2000 was a leap year, but 2100 will not be.

The Gregorian calendar came into effect immediately in Catholic Europe. Protestant areas did not do so until 1700, Great Britain until 1753, Japan in 1873, and Russia already converted into the Soviet Union in 1918.

Source-listindiario.com