December 1, 2021
The Gregorian calendar or Gregorian calendar is a chronology with Christian roots that is currently used in more than 95% of the world and is an international calendar. This chronology is derived from the Julinius chronology of the birth of Jesus and was first proposed by Alvesius Lilius, a Calabrian physician. The coronation adjustment of this calendar was accepted by Pope Gregory XIII on February 24, 1582, and has since become known as the Gregorian (Gregorian) calendar, but in Iran and the Arab world it is called the Gregorian calendar. The Gregorian calendar was first accepted among European Catholic countries and then among Protestants and Orthodox. Among European countries, Greece was the last country to adopt this calendar in 1923. Japan, Korea, and China adopted the 1895, 1872, and 1912 calendars, respectively. Today, in most countries of the world, as well as in most Islamic countries, the Gregorian calendar is known as the official calendar. Egypt ratified it in 1875 and Turkey on December 26, 1925, and on January 1, 1926, it adopted the Gregorian calendar. Saudi Arabia is the last Islamic country to choose the Gregorian calendar as the official calendar of the country in 2016 and replace the Umm al-Qura calendar (based on the Hijri lunar calendar). According to global statistics in August 2020, Iran with a population of 83 million, Afghanistan with a population of 38 million Ethiopia, with a population of 112 million, and Nepal, with a population of 29 million, are the only countries in the world where the Gregorian calendar is not yet considered an official calendar. They are not a world and have no application outside these countries.