ABC of the Sukuma Calendar

Abstract

The aim of this study had been to document and to astronomically mimic in an algorithm the undocumented ancient lunar calendar of the Sukuma and that of the Nyamwezi sibling tribe of Tanzania which is at the verge of perishing due to the perishing of living memory about that calendar. It had been found that the Sukuma calendar marks its end of the sidereal year at the Sukumaland “Jidiku” position of Earth in its trajectory around the Sun which is the December Solstice astronomically fitting on the Gregorian 23rd December. The stereotype is that the ancient Sukuma of Kishapu tallied up the elapsing days since the first appearance of the ndimila on the horizon day-to-day using 64 pebbles to get to the “Jidiku” and later developed that method of tallying days into the fully fledged “isolo” game of counting pebbles. Subsequent to the determination of the “Jidiku” position, the algorithm to compute the Sukuma lunar New Year was developed basing on the technique of computing the Jewish calendar in essence whereby the number of lunar-tagged days elapsed to the beginning of a 19-year lunar cycle since 01st January year 0000 get compared with the number of solar days elapsed to the beginning of a 19-year Gregorian cycle since 01st January year 0000 to get the difference in number of days short to the next new moon which mark the Sukuma lunar New Year lying between 23rd December and 22nd January. By adding the number of days short to the next new moon at the beginning of a 19-year Gregorian cycles to a series-tagged increment of days - which is a product of 19 and a within-cycle-relative year of the running year (lying between 0 and 18) - the within-cycle lunar New Year gets computed. The lengths of the consecutive lunar months between two consecutive Sukuma lunar New Years were found to fit in a model of repeating 30-to-29 days. It was further found that the Nyamwezi lunar New Year falls one lunar month before the Sukuma lunar New Year and that a Nyamwezi lunar New Year within a 19-year Gregorian cycle is gotten by adding a series-tagged decrement of days - which is a product of 11 and a within-cycle-relative year of the running year - to the begin-of-cycle number of days short to the next new moon.