Gregorian calendar

The Gregorian calendar is the calendar widely used in the Western world. A modification of the Julian calendar, it was first proposed by the Neapolitan doctor Aloysius Lilius, and was decreed by Pope Gregory XIII, for whom it was named, on 24 February 1582 (Note: The papal bull Inter gravissimas was signed in the year 1581 for unknown reasons, but printed on 1 March in 1582. Although 1581 is often attributed to the use of years beginning on 25 March by the papacy, other contemporaneous papal bulls have years that do not agree with March years, let alone years since a pope was named or other types of years.)

Related Topics:
Calendar - Western world - Julian calendar - Neapolitan - Aloysius Lilius - Pope Gregory XIII - 24 February - 1582 - Papal bull - Inter gravissimas - 1581 - 1 March - 25 March

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The Gregorian calendar was devised because the mean year in the Julian Calendar was a little too long, causing the vernal equinox to slowly drift earlier in the calendar year.

Related Topics:
Year - Vernal equinox - Calendar year

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The dates in this article may be in either the Julian or Gregorian calendars — Julian for dates before the calendar change and Gregorian for dates after it. They are indiscriminately mixed with dates from the other calendar in the linked "Month day" article.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~