The Ethiopian calendar (; ) is the principal calendar used in Ethiopia and also serves as the liturgical calendar for Christians in Eritrea and Ethiopia belonging to the Orthodox Tewahedo churches, Eastern Catholic Church and Coptic Orthodox Church. It is a solar calendar (the older Alexandrian or Coptic calendar brought to Ethiopia by missionaries) which in turn derives from the Egyptian calendar, but like the Julian calendar, it adds a leap day every four years without exception, and begins the year on August 29 or August 30 in the Julian calendar. A seven- to eight-year gap between the Ethiopian and Gregorian calendars results from an alternate calculation in determining the date of the Annunciation of Jesus.