Coptic calendar Roman Emperor Augustus imposed the Decree upon Egypt as its official calendar (although it was unsynchronized with the newly introduced Julian calendar which had erroneously been intercalating leap days every third year due to a misinterpration of the leap year rule so as to apply inclusive counting). To distinguish it from the Ancient Egyptian calendar, which remained in use by some astronomers until medieval times, this reformed calendar is known as the Coptic calendar. Its years and months coincide with those of the Ethiopian calendar but have different numbers and names. The Coptic year is the extension of the ancient
Zoroastrian calendar Zoroastrian Seasonal-Year Society. In 1906, the society published its proposal for a Zoroastrian calendar which was synchronised with the seasons. This "Fasli" calendar, as it became known, was based on the Jalali calendar introduced in 1079 during the reign of the Seljuk Malik Shah and which had been well received in agrarian communities. The Fasli proposal had two useful features: a leap-day once every four years, and harmony with the tropical year. The leap-day, called "Avardad-sal-Gah" (or in Pahlavi: "Ruzevahizak"), would be inserted, when required, after the five existing "Gatha" days at the end of the year. New Year's Day