The Akan calendar is based on what the Akan call 'forty days'; Adaduanan (da=day, aduanan=forty). Close examination of the cycle reveals forty-two different days, with the forty-third being the same as the first.
The composition or construction of the Adaduanan cycle appears to be based on an older six-day week, still extant in some northern Guan communities such as the Nchumuru The six-day week is referred to as Nanson (literally seven-days) and reflect the lack of zero in the numbering systems; the last day and the first day are both included when counting the days of a week.
|Fo||Council day (passing sentence); judgement day|
|Nwuna||Sleep (death) day; funerals day; covered day|
|Nkyi||Behind (hate-taboo) day; destroyed day.|
|Kuru||Town (ie political) day; royal day|
|Kwa||For nothing ('just like that', free, unrestrained) day, servant day|
|Mono||Fresh (starting) day|
Seven-day week which may have been brought south with itinerant traders from the savannah is referred to as Nawotwe (literally eight days). Like Nanson the last day and the first day are both included when counting the days of a week.
|Dwo (Monday)||Quiet (peace) day; calm.|
|Bena (Tuesday)||Birthday of ocean; heat, boiling, cooking.|
|Wukuo (Wednesday)||Birthday of Spider (reverse or mortal version of God)|
|Ya (Thursday)||Birthday of Earth (a woman); power.|
|Afi (Friday)||Fertility (in some Fante States, birthday of Earth).|
|Mene (Saturday)||Birthday of Supreme or Sky God (a man); respected, ancient|
|Kwasi (Sunday)||Under Day (awiase= under the sun); universe, everything.|
When the six-day week is counted side-by-side with the seven-day week it takes a total of forty-two days to reach all combinations. The forty-two day cycle shown here, as recorded in Kwahu, is the same recorded for the Brong (ie Bono Techiman) a state Northwest of the Asante.
Within the Adaduanan cycle are found four special days collectively called dabone (bone=evil); Fodwo, Awukudae, Fofi and 'Akwasidae.
The forty-two day cycle may be thought to begin on Fodwo and the other three dabone follow in nine day intervals; Awukudae on the tenth day, Fofi on the nineteenth day, and Akwasidae on the twenty-eighth day. It takes a further fourteen days to complete the Adaduanan.
When Kuru (from kurow=town) of the six-day week coincides with a Wednesday of the seven-day week (on Kuru-Wukuo), or with a Sunday of the seven-day week (on Kuru-Kwasi), the two dabone most closely related to stool rites, Awukudae and Akwasidae (Wuko-Adae and Kwasi-Adae) are celebrated.
These two 'bad' days are called adae (perhaps deriving from da=sleep and eye=well, impling that the ancestors should lie comfortably), and are closely associated with politico-ritual symbols of gerontocracy sanctified or sanctioned by ancestor worship.
No funerals may be held and no news of death may reach the ears of a chief (the living shrine of his ancestors) while libations of alcohol and offerings of food are made to the blackened stools (the permanent physical shrines of those ancestors) on an adae.
When Fo of the six-day week coincides with a Monday or Friday, the two dabone most closely related to tutelary spirits are celebrated (Fodwo and Fofi) are closely associated with medico religious symbols or purification and the intervention of anthropomorphic spirits inhabiting natural objects such as rivers and cave
The Asante sent messengers to Brong(ie Techiman) when in doubt when to hold any festival, for the Brong were 'keepers of the King's calendar.'
These four 'holidays' are not complete vacations from all labour. No farming may be carried out on any dabone but work per se is not banned. Hunting and gathering are usually permitted and the people may go to their farms to carry home firewood or food reaped the previous day, so long as no weeding of farms is done. Often communal labour is performed on those dabone which are not filled with ritual and ceremonial activities.
Apart from the four standard dabone, some Gods may celebrate other days of the cycle. For example, the God Burukung, which was the senior god of the Guan    on the Kwawu Afram Plains, and now the chief of the Kwawu abosom (tutelary spirits), since the sixteenth century Akan take-over of Kwawu (the principle shrine being a large, striking inselberg on the northern slopes of the Kwawu escarpment), celebrates the principal rites on Kwadwo (the Monday following Akwasidae).
The cult of Akonnedi, god of Late (Larteh) in Akwapim, which has branches in Kwawu, observes its most frequent public rites on 'Nkyi-Mene' or 'Memenada Adapa' (the day prior to 'Akwasidae').
Various other gods in Kwawu are honoured on various other days in the forty-two day cycle.
The Adaduanan do not precisely comprise the annual calendar, because nine cycles total 378 days instead of 365 1/4. Eight cycles yield only 336 days. Annually celebrated rites of the different Akan groups, such as the first yam eating festival, Odwira (ablution) or Afahye (public festival), are therefore celebrated each year on different days of the year. The priests of the various gods, in consultation with the various gods and ancestors, determine which Adaduanan cycle to choose for the annual rites, usually depending upon the ripening of the crops. Any series of annual rites is observed on the same days of the Adaduanan each year, although not on the same days of the year as reckoned by the Gregorian calendar.
The various Adaduanan cycles within the year are given a number of appellations, which are not the same from place to place, and of course never quite the same from year to year, since there are less than nine and more than eight cycles in any one year. Opepon (Ope=harmatan, dry season, pon=supreme) for example, more or less corresponds to the Adaduanan which appears about January-February in the middle of the dry season. Every three years or so, one of the nine named Adaduanan is omitted from the year because of the extra thirteen days gained when observing nine cycles a year. The names of the Adaduanan are therefore flexible and vary over time and cline.
Today some of the names for the Adaduanan cycles have been arbitrarily applied to the Gregorian calendar of twelve months by some Akan scholars, although there is no traditional basis for such a translation. For example, Opepon is now used for the Akan word for January even though in the traditional Akan calendar there is no concept exactly corresponding to the Roman month of of January (Janus the god facing the past and future). The beginning and end of each Akan year tends to be the various yam festivals celebrated around August or September.
The lunar cycle and twenty-eight 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 twenty-eight days rather than the thirty or thirty-one 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 on Adaduanan.
It is quite easy to calculate the Akan calendar from the Gregorian calendar once a few keys are known. Understandably there is no equivalent in English to the six day week. The seven day week of the English and Akan calendars are, however, equivalent, with the suffix -da (day) added to the names of the days in the above list (Sunday is Kwasida, saturday is Memenada, and so on). Every second year or so Easter occurs on an Akwasidae. In 1978 there are nine Akwasidae, celebrated on 8 January, 19 February, 2 March, 14 May, 25 June, 30 July, 6 August, 17 September, 29 October and 10 December, that is every sixth Sunday. The first four dabone of 1978 were Akwasidae (8 January), Fodwo (23 January), Awukudae (1 February), and Fofi (10 February). Other dabone may be calculated infinitely from these adding or subtracting six-week intervals.
The synthesis of a six-day week and a seven-day week, forming the forty-two day Adaduanan cycle may be added to numerous other items of evidence to support a theory of the origins and development of Akan culture which suggests that it is based on cultural diffusion and a compromise of observances having diverse origins.