The Ethiopian calendar is the principal calendar used in Ethiopia and also serves as the liturgical year for Christians in Ethiopia and Eritrea belonging to the Ethiopian Orthodox Tewahedo Church, Eritrean Orthodox Tewahedo Church, Eastern Catholic Churches, the Coptic Orthodox Church of Alexandria, and P'ent'ay Churches. The Ethiopian calendar is a solar calendar that has more in common with the coptic 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 gap of seven to eight years between the Ethiopian and Gregorian calendars results from an alternative calculation in determining the date of the Annunciation. The Ethiopic calendar has twelve months of thirty days plus five or six epagomenal days, which comprise a thirteenth month. The Ethiopian months begin on the same days as those of the Coptic calendar, but their names are in Ge'ez. A sixth epagomenal day is added every four years, without exception, on August 29 of the Julian calendar, six months before the corresponding Julian leap day. Thus the first day of the Ethiopian year, 1 Mäskäräm, for years between 1900 and 2099, is usually September 11. It falls on September 12 in years before the Gregorian leap year, however.
Enkutatash is the word for the Ethiopian New Year in Amharic, the official language of Ethiopia, while it is called Ri'se Awde Amet in Ge'ez, the term preferred by the Ethiopian & Eritrean Orthodox Tewahedo Churches. It occurs on September 11 in the Gregorian Calendar; except for the year preceding a leap year, when it occurs on September 12. The Ethiopian Calendar Year 1998 Amätä Məhrät began on the Gregorian Calendar Year on September 11, 2005. The Ethiopian Years 1992 and 1996, however, began on the Gregorian Dates of 'September 12th 1999' and '2003' respectively. This date correspondence applies for the Gregorian years 1900 to 2099. The Ethiopian leap year is every four without exception, while Gregorian centurial years are only leap years when exactly divisible by 400; thus a set of corresponding dates will most often apply for a single century. As the Gregorian year 2000 is a leap year, the current correspondence lasts two centuries instead. The start of the Ethiopian year falls on 29 or 30 August. This date corresponds to the Old-Style Julian Calendar; therefore, the start of the year has been transferred forward in the currently used Gregorian Calendar to 11 or 12 September. This deviation between the Julian and the Gregorian Calendar will increase with the passing of the time. One may observe the real start date in future centuries in a Gregorian to Ethiopian .
Eras
To indicate the year, Ethiopians and followers of the Eritrean churches today use the Incarnation Era, which dates from the Annunciation or Incarnation of Jesus on March 25, AD 9, as calculated by Annianus of Alexandriac. 400; thus its first civil year began seven months earlier on August 29, AD 8. Meanwhile, Europeans eventually adopted the calculations made by Dionysius Exiguus in AD 525 instead, which placed the Annunciation eight years earlier than had Annianus. This causes the Ethiopian year number to be eight years less than the Gregorian year number from January 1 until September 10 or 11, then seven years less for the remainder of the Gregorian year. In the past, a number of other eras for numbering years were also widely used in Ethiopia and the Kingdom of Aksum.
The most important era – once widely used by the Eastern Christianity, and still used by the Coptic Orthodox Church of Alexandria – was the Era of Martyrs, also known as the Diocletian Era, or the era of Diocletian and the Martyrs, whose first year began on August 29, 284. Respective to the Gregorian and Julian New Year's Days, 3 to 4 months later, the difference between the Era of Martyrs and the Anni Domini is 285 years. This is because in AD 525, Dionysius Exiguus decided to add 15 Metonic cycles to the existing 13 Metonic cycles of the Diocletian Era to obtain an entire 532 year medieval Easter cycle, whose first cycle ended with the year Era of Martyrs 247 equal to year DXXXI. It is also because 532 is the product of the Metonic cycle of 19 years and the solar cycle of 28 years.
Around AD 400, an Alexandrine monk called Panodoros fixed the Alexandrian Era, the date of creation, on 29 August 5493 BC. After the 6th century AD, the era was used by Egyptian and Ethiopian chronologists. The twelfth 532 year-cycle of this era began on 29 August AD 360, and so 4×19 years after the Era of Martyrs.
Bishop Anianos preferred the Annunciation style as New Year's Day, 25 March . Thus he shifted the Panodoros era by about six months, to begin on 25 March 5492 BC. In the Ethiopian calendar this was equivalent to 15 Magabit 5501 B.C.. The Anno Mundi era remained in usage until the late 19th century.
Leap year cycle
The four-year leap-year cycle is associated with the four Evangelists: the first year after an Ethiopian leap year is named the John-year, followed by the Matthew-year, and then the Mark-year. The year with the sixth epagomenal day is traditionally designated as the Luke-year. There are no exceptions to the four-year leap-year cycle, like the Julian calendar but unlike the Gregorian calendar.
Months
These dates are valid only from March 1900 to February 2100. This is because 1900 and 2100 are not leap years in the Gregorian calendar, while they are still leap years in the Ethiopian calendar, meaning dates before 1900 and after 2100 will be offset.
