On this day, 443 years ago, on October 5, 1582 (September 19, 1582, the lunar calendar), Pope Gregory XIII established the current common Gregorian calendar. Pope Gregory XIII (January 7, 1502-April 10, 1585), also translated as Gregory XIII, Gregory XIII, Pope Gregory XIII, born Ugo Boncompagni, the 227th Pope (reigned May 13, 1572-April 10, 1585). He reformed the calendar in 1582 AD, forming today's Gregorian calendar. The Catholic Diocese of Macau was established by his order in 1576. The current Gregorian calendar is the Gregorian calendar, which is also translated into Gregorian calendar and Gregorian calendar. It was a calendar established by Italian doctor and philosopher Aloysius Lilius who reformed the Julian calendar and promulgated it by Pope Gregory XIII in 1582. The Gregorian calendar is a type of Gregorian calendar. It was officially adopted in China in 1912, replacing the traditionally used China calendar summer calendar (lunar calendar). The traditional China calendar is a lunisolar calendar, so the Gregorian calendar is also called Gregorian calendar, Western calendar, and New Calendar in Chinese. The Gregorian calendar is the same as the Julian calendar. The Gregorian calendar also has a leap day at the end of February every four years. However, the Gregorian calendar specifically stipulates that unless it is divisible by 400, all century years (divisible by 100) will not have a leap day; thus, every four hundred years, the Gregorian calendar has only 97 leap years, which is 3 fewer than the Julian calendar. The average length of the Gregorian calendar year is 365.2425 days, which is close to the average return year of 365.24219 days, which is about one day in every 3300 years, and closer to 365.24237 days in the return year of the vernal equinox, which is about one day in every 8000 years; while the Julian calendar year is 365.25 days, which is about one day in every 128 years. By 1582, the vernal equinox day (March 21) in the Julian calendar and the actual time when the earth revolved to the vernal equinox were 10 days apart. Therefore, when the Gregorian calendar came into effect, it was also stipulated that the day after Thursday, October 4, 1582, in the original Julian calendar, would be Friday, October 15, 1582, that is, 10 days would be deleted, but the cycle of the original week remained unchanged. The Gregorian calendar follows the Julian calendar, starting from the traditional year of the birth of Jesus, and is called "AD", also known as "AD". Pope Gregory XIII officially promulgated the Gregorian Calendar to replace the Julian Calendar Comment: Calendar is gradually being used uniformly around the world.