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
Julian calendar before the Julian reform, that the tropical year was slightly shorter than 365.25 days, the calendar did not compensate for this difference. As a result, the calendar year gains about three days every four centuries compared to observed equinox times and the seasons. This discrepancy was largely corrected by the Gregorian reform of 1582. The Gregorian calendar has the same months and month lengths as the Julian calendar, but, in the Gregorian calendar, year numbers evenly divisible by 100 are not leap years, except that those evenly divisible by 400 remain leap years. (Even then, the Gregorian calendar diverges from