The Berber calendar is the agricultural calendar traditionally used by Berbers. It is also known as the fellaḥi (ﻓﻼّﺣﻲ "rustic" or ﻋﺠﻤﻲʿajamī "foreign" calendar). The calendar is utilized to regulate the seasonal agricultural works.
The agricultural Berber calendar still in use is almost certainly derived from the Julian calendar, introduced in the Roman province of Africa at the time of Roman domination. The names of the months of this calendar are derived from the corresponding Latin names and races of the Roman calendar denominations of Kalends, Nones and Ides exist: El Qabisi, an Islamic jurisconsult by Kairawan who lived in the 11th century, condemned the custom of celebrating "pagans'" festivals and cited, among traditional habits of North Africa, that of observing January Qalandas ("Kalends"). The length of the year and of the individual months is the same as in the Julian calendar: three years of 365 days followed by a leap year of 366, without exceptions, and 30- and 31-day months, except for the second one that has 28 days. The only slight discrepancy lies in that the extra day in leap years is not usually added at the end of February, but at the end of the year. This means that the beginning of the year (the first day of yennayer) corresponds to the 14th day of January in the Gregorian calendar, which coincides with the offset accumulated during the centuries between astronomical dates and the Julian calendar.