The Ethiopian calendar is the main calendar used in Ethiopia. It 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 which comes from the Egyptian calendar. But like the Julian calendar, it adds a leap day every four years. It 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.