The Igbo calendar is a traditional timekeeping system used by the Igbo people of southeastern Nigeria. Unlike the Gregorian calendar which has 7 days in a week, the Igbo calendar has 4 days in a week, 7 weeks in a month, 28 days in a month, 13 months in a year, 91 weeks in a year, and 364 days in a year.

The four market days which make up the native week in Igboland are namely; Eke, Orie, Afo, Nkwo. The Igbo man works in the farm for only three days and rests completely from farming on the fourth day. Eke is usually the holy day of obligation when people rest from farming, however some communities can decide to adopt any of the four market days for their rest from farming. It is considered abominable for anybody to farm on the holy day of obligatory rest.

These four market days also serve as a form of identification. The traditional names of most Igbo people are derived from the market day on which they were born.

MARKET DAY IGBO NAME DERIVED
Male Female
Eke Okeke or Nweke Mgbeke
Orie Okorie or Nwoye Mgborie
Afo Okafor or Nwafor Mgbafor
Nkwo Okonkwo or Nwankwo Mgbokwo

The 13 months in the Igbo calendar each have specific names, often related to agricultural or cultural events. Some of these month names include:

  1. Onwa Mbụ (First Month)
  2. Onwa Abụo (Second Month)
  3. Onwa Atọ (Third Month)
  4. Onwa Anọ (Fourth Month)
  5. Onwa Agwụ (Month of Exhaustion, typically during the peak of the rainy season)
  6. Onwa Ifejioku (Month of the Yam Spirit, associated with the New Yam Festival)
  7. Onwa Ọlọchukwu (Month of the Harvest)

(Note: The complete list and order of months can vary slightly between different Igbo communities.)