A reader who looks up the Yoruba calendar today will usually meet Kojoda: a reckoning that keeps the four day week, groups the weeks into a year of ninety one of them, opens that year in early June at the Ifa festival, and numbers the years from a remote epoch, so that a recent year is given as something over ten thousand. It is worth separating what is attested from what is reconstructed, because the two are almost always presented together.
The four day week is old. It is in the earliest written records of the language, it governs the market cycle, and it is described in every substantial ethnography of Yoruba religion. The assignment of days to orisha is old. The traditional agricultural and festival year, ordered by the festivals of particular towns, is old.
The numbered Kojoda era is not. It is a twentieth century construction, associated with Yoruba cultural revival and taken up energetically by diaspora Ifa organisations, and it supplies a continuous era to a tradition that reckoned by cycles, by reigns and by festivals and had no era at all. That does not make it worthless. It is a real thing that real communities keep, and it belongs in the record as what it is: a modern reckoning built on an old week. What would be wrong is to let the year number pass as though it had been counted since the epoch it names.