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
Calendar reform entirely, to make the calendar perennial. Around 1930 Colligan invented the Pax Calendar, which avoids off-calendar days by adding a 7-day leap week to the 364-day common year for 71 out of 400 years. In 1993, Lloydine and José Argüelles founded the World Thirteen Moon Calendar Change Peace Movement. Dividing the years into 52 weeks creates 13 months of 28 days (4 weeks), and 4 quarters of 91 days (13 weeks). This creates months and quarters of fixed, even duration, but not quarters containing a whole number of months. Instead of a leap week or an extra day and a