Gregorian calendar

基本解释

The Gregorian calendar was not widely adopted across the world until much later.
格裡高利歷法（公歷）直到很久以後都未被世界採用。
With the reform of the calendar under Charles IX, the Gregorian Calendar was introduced, and New Year's Day was moved to January 1.
後來隨著查理九世對日歷的改革，格裡高裡歷被引進，新年也隨之移到了1月1日。
ORIGIN: the exact origin of April Fool's Day isn't known, but many think it began in France around 1582 with the introduction of the Gregorian Calendar, which is the most widely used calendar today.
起源：四月愚人節的確切起源已不可考，不過很多人認爲這個節日是起源於1582年前後的法國，在公歷被引進之後——公歷就是我們到今天還在使用的歷法。

We controlled for other well-known fixed calendar (we call them Gregorian anomalies), notably,day of the week effect, like Monday,January effect, Halloween effect, and none of those factors explained results.

The Gregorian calendar is used today in the large majority of countries.
UNESCO: International Women’s Day: why the 8 of March?
Clavius started his career by taking on the reform of the Gregorian calendar, a project partly inspired by Copernicus and his book.
FORBES: A Long Forgotten Father of the Scientific Revolution
Britain adopted the Gregorian calendar only in 1752.
ECONOMIST: Late for the date

the revision of the Julian calendar introduced in 1582 by Pope Gregory XIII and still in force, whereby the ordinary year is made to consist of 365 days and a leap year occurs in every year whose number is divisible by four, except those centenary years, such as 1900, whose numbers are not divisible by 400