The Igbo week has four days

Izu, ọnwa, arọ

The four days make an izu, a week. Seven of those weeks make an ọnwa, a month of twenty-eight days that follows the moon, and thirteen of those months make a year. That is why the Igbo year doesn’t begin in January: the Eze Nri proclaims its start, usually in February, at the festival called Ịgụ Arọ.

How this page counts the days

No university or palace publishes a day-by-day table of the Igbo week against Gregorian dates. What exists is agreement in practice, and this page follows it: 1 January 2026 was Orie. Counting forward and back from there matches the calendars listed below, including one tabulated for 2000 to 2050 before 2009, and it matches the 2012 Ịgụ Arọ at Nri, which fell on an Nkwọ.

Two things are worth saying plainly. A day traditionally turns at sundown, not at midnight, so an evening belongs to the day that follows. And some communities keep the cycle a step apart from this count. If your village counts it differently, your village is right for your village.

Where the count comes from

• Igbo calendar, Wikipedia: the four days, the izu, and the caution that the calendar isn’t synchronised everywhere.
• Igbo market days, 2000 to 2050, Emeka Ezekwe: a day-by-day table published before 2009, anchored at 1 January 2000 = Eke.
• Igbo calendar, Silver Ibenye-Ugbala: the online form of a published book-length calendar.
• Izu Igbo calendar, Odinani Mystery School: gives the tone-marked forms and the sundown rule.
• Igbo market calendar, marketdays.ng: publishes its own anchor: 10 August 2026 was Afọ.