1582

1582 (MDLXXXII) was a common year starting on Monday in the Julian calendar, and a common year starting on Friday (link will display full calendar) of the Proleptic Gregorian calendar. This year saw the beginning of the Gregorian calendar switch, when the papal bull Inter gravissimas introduced the Gregorian calendar, adopted by Spain, Portugal, the Polish–Lithuanian Commonwealth and most of present-day Italy from the start. In these countries, the year continued as normal through Thursday, October 4; the next day became Friday, October 15, like a common year starting on Friday. France followed two months later, letting Sunday, December 9 be followed by Monday, December 20. Other countries continued using the Julian calendar, switching calendars in later years, and the complete conversion to the Gregorian calendar was not entirely done until 1923.

Events

January–March

January 2 – The University of Würzburg is refounded.

January 15 – Russia cedes its conquered areas in Livonia (Northern Latvia and Southern Estonia), to the Polish–Lithuanian Commonwealth.

February 10 – François, Duke of Anjou, arrives in the Netherlands, where he is personally welcomed by William the Silent.

February 24 (Julian) (March 6 Gregorian) – Pope Gregory XIII proclaims the Gregorian calendar, to come into effect in October. Under the order, the date on the Julian calendar will be advanced by 10 days in order to synchronize the calendar date back to the equinoxes and solstices, since the gap has been increasing by one day every 100 years since the 6th century and is 10 days off schedule.