The IGBO CALENDAR APP is a free tool with the main purpose of helping its users to determine the corresponding igbo market day (afọ, nkwọ, eke or orie) of any Gregorian Calendar date within reasonable time period (specifically between 1900 and 2100). The four market days that make up "ofu izu" (one week) in Igbo traditional calendar system are very significant in Igbo communities especially when fixing traditional events and cultural ceremonies. Any Calendar that can assist to determine the Ig