Adoption of the Gregorian calendar liege lord, the King of Poland, it agreed in 1611 to do so. So 22 August was followed by 2 September 1612. However, this calendar change did not apply for other territories of the Hohenzollern, such as Berlin-based Brandenburg, a fief of the Holy Roman Empire. Through Ole Rømer's influence, Denmark in 1700, which then included Norway, adopted the solar portion of the Gregorian calendar with Sunday, 18 February 1700, being followed by Monday, 1 March 1700, simultaneously with the Brandenburg-Pomerania and other Protestant estates of the Holy Roman Empire. None of these states adopted the lunar portion, instead calculating
Gregorian calendar always obtained by doubling (the "bissextum" (twice sixth) or bissextile day) until the late Middle Ages. The Gregorian calendar is proleptic before 1582 (assumed to exist before 1582). The following equation gives the number of days (actually, dates) that the Gregorian calendar is ahead of the Julian calendar, called the "secular difference" between the two calendars. A negative difference means the Julian calendar is ahead of the Gregorian calendar. where formula_2 is the secular difference and formula_3 is the year using astronomical year numbering, that is, use for BC years. formula_4 means that if the result of the division is