The Gregorian calendar is the calendar that is most widely used in the world today. It was invented by Pope Gregory XIII in 1582 and is named after him. The purpose of the calendar was to make sure that the date of Easter always fell on the same day.

The previous calendar, known as the Julian calendar, had been in use since the time of Julius Caesar. However, there was a problem with this calendar: it did not accurately reflect the length of a year. The Julian year was 365.25 days long, which was slightly too long. This meant that over time, the dates of the seasons and the date of Easter were drifting out of sync.

To correct this problem, Pope Gregory XIII commissioned a group of astronomers and mathematicians to come up with a new calendar. They came up with a system that involved skipping certain leap years. According to the new calendar, years that are divisible by 100 are not leap years, unless they are also divisible by 400. This means that the year 2000 was a leap year, but 1900 was not.

The new calendar was implemented in Catholic countries in 1582, and gradually adopted by other countries over time. However, it was not adopted by Protestant countries until much later. In England, for example, the calendar was not adopted until 1752.

Today, the Gregorian calendar is the standard calendar used by most of the world's countries. It is accurate to within a few seconds per year, which means that it will not need to be corrected for thousands of years.

свернуть