An Ethiopian year is comprised of 13 months, and is seven years behind the Gregorian calendar. Truth is, Ethiopians celebrated the new millennium on September 11, 2007; this is because the Ethiopians continued with the same calendar that the Roman church amended in 525 AD unlike the rest of the world.
Ethiopia is the only country in the world with 13 months and their New Year starts on September 11 (September 12 in leap years), which implies that they are 7½ years behind Nigeria. As a matter of fact, they are two months into 2013 while Nigerians are in 2020. #HistoryVille