Swedish calendar Julian calendar. An extra day was added to February in the leap year of 1712, thus giving it a unique 30-day length (February 30). In 1753, one year later than England and its colonies, Sweden introduced the Gregorian calendar. The leap of 11 days was accomplished in one step, with February 17 being followed by March 1. Easter was to be calculated according to the Easter rules of the Julian calendar from 1700 until 1739, but from 1700 to 1711, Easter Sunday was dated in the anomalous Swedish calendar, described above. In 1740, Sweden finally adopted the "improved calendar" already
Century leap year Century leap year In the Gregorian calendar, a year ending in "00" that is divisible by 400 is a century leap year, with the intercalation of February 29 yielding 366 days instead of 365. Century years (divisible by 100) that are "not" divisible by 400 are not leap years but common years of 365 days. For example, the years 1600, 2000, and 2400 are century leap years since those numbers are divisible by 400, while 1700, 1800, 1900, 2100, 2200, and 2300 are common years despite being divisible by 4. Leap years divisible by 400 always start on a Saturday;