A Working Calendar, Still Kept

The izu is not a reconstructed or ceremonial survival. It remains the working week by which markets are scheduled across Igboland today, run alongside the Gregorian week rather than replaced by it, so a given date can be described by either reckoning depending on context: civil affairs by the Gregorian calendar and market timing by the older four day cycle.

Among practitioners of Odinani, Igbo traditional religion, and in syncretic practice that blends indigenous observance with Christianity, the four days retain their distinct ritual associations, and which day of the izu a person or an event falls on can still carry meaning beyond simple scheduling. The four day week's survival alongside, rather than beneath, the imported Gregorian calendar is itself notable: unlike calendars that were formally replaced by colonial administration, the izu kept its practical function because the markets it timed continued to matter economically, giving the reckoning a durability that purely religious calendars without an economic anchor have sometimes lacked. The atlas records the tradition attributing its institution to Nri as oral history rather than as settled chronology, since the surviving documentation comes from ethnographic recording long after the tradition describes its own origin, a gap no source has yet closed.