Igu Aro is the proclamation of Igbo Lunar Calendar, a ritual performed every year at Nri in Anaocha LGA of Anambra State.

Nri needs no introduction, but for benefit of those that are not of Igbo stock, Nri is a holy city which was founded in 900AD and is the ancestral homeland of the Igbos, where most of the culture and traditions of the Igbo race as practiced today evolved. Every Igbo community/settlement aspires to establish its authenticity by tracing its origin to Nri Kingdom. According to Major Arthur Glyn Leonard in his book, “The Lower Niger and Its Tribes”, “The Street of Nri family is the street of gods through which all who die in other parts of Igboland pass to the land of the spirit”.

Having said that, the proclamation of the Igbo Lunar Calendar is done in February, which is the first month of the year. Lunar Months approximate the mean length of the synod month of approximately 29.53059 days (29 days, 12 hours, 44 minutes and 3 seconds). A lunar calendar is a calendar that is based on cycles of the moon phase. For some lunar calendars, the first day of the month is the day when eclipse moon appears in a particular time zone. Many other lunar calendars are based on the first sighting of a lunar crescent.