You may have wondered about the origin of the calendar we use in the western world. So what would its origin really be? How was it calculated? Below is a short history of the Gregorian calendar, which is used today in most of the world.
The Gregorian calendar came about as a result of a modification in the Julian calendar, carried out in 1582, to adjust the calendar year, the calendar year, to the solar year, resulting from the ellipse movement performed by the Earth around of the sun. Before Julius Caesar (100 b. Ç. – 44 a. C.), the calendar in force in Rome was divided into 355 days and 12 months, which caused a great maladjustment over time, as the seasons began to occur on different dates. When he became dictator of the Roman Republic, Julius Caesar decided to reform the calendar to make it fit natural time again.
For this, it was necessary to create, in 46 a. C., a year with 15 months and 455 days to make up for the lag, this year was known as the “year of confusion”. The reform of Julius Caesar instituted the year after 45 a. Ç. with 365 days and six hours, divided into 12 months, which managed to solve the problem for a while. The six hours left over each year would be compensated every four years with the inclusion of one more day in February, the leap days.
However, the gap between the calendar year and the natural year still persisted, and during the Middle Ages there were several attempts to resolve it. The Council of Trent, held in 1545, decided to change the Church's calendar, leaving Gregory XIII to institute the new calendar, which would be called Gregorian calendar in his honor. To match the date of Easter with the spring equinox in the Northern Hemisphere, Pope Gregory XIII ordered the day following October 4, 1582, to become October 15th. An 11-day leap! To bridge the gap, leap days would not occur in centennial years (ending in 00) unless they were exactly divisible by 400.
Most of the Catholic world accepted the change, but several countries rejected the change, making more than one calendar exist in the Christian world. The last countries to adopt the Gregorian calendar in Europe were Greece, in 1923, and Turkey, in 1926.
By Tales Pinto
Graduated in History
