Akan calendar each Akan year tends to be the various yam festivals celebrated around August or September. The lunar cycle and 28-day month are not carefully observed, except by the coastal Akan who are interested in tides as they affect fishing. Still, the month is known as "bosome". It consists of 28 days rather than the 30 or 31 days of the Gregorian calendar. Three "bosome" make two Adaduanan. Since the arrival of Swiss missionaries from Basel in the early nineteenth century, Christian Akan scholars have tended to 'Akanize' the Roman calendar rather than observe, analyse and explain the Akan calendar based
Adoption of the Gregorian calendar 12 days, only 11 were skipped, and the day of the week was repeated on successive days, because at the same time the International Date Line was moved, from following Alaska's eastern border with Canada to following its new western border, now with Russia. Many of the countries of eastern Europe were Eastern Orthodox or Islamic and adopted the Gregorian calendar much later than western Christian countries. Roman Catholic countries such as the Polish–Lithuanian Commonwealth adopted the "new style" (N.S.) Gregorian calendar in 1582 (switched back in 1795 after Third Partition of Poland), but the switch to the Gregorian calendar