Ethiopian calendar
Like the Coptic calendar, the Ethiopic calendar has twelve months of 30 days plus five or six epagomenal days, which make up a thirteenth month. The Ethiopian months begin on the same days as those of the Coptic calendar. The names of the days are in Ge'ez. The sixth epagomenal day is added every four years without exception on August 29 of the Julian calendar. This occurs six months before the Julian leap day. Thus the first day of the Ethiopian year, 1 Mäskäräm, for years between 1900 and 2099 (inclusive), is usually September 11 (Gregorian). It, however, falls on September 12 in years before the Gregorian leap year. The Ethiopian New Year falls on September 11 of the Gregorian calendar. On leap years it falls on September 12.