Page "Chinese calendar" Paragraph 14

In 1258, when both North China and the Islamic world were part of the Mongol Empire, Hulagu Khan established an observatory in Maragheh for the astronomer Nasir al-Din al-Tusi at which a few Chinese astronomers were present, resulting in the Chinese-Uighur calendar that al-Tusi describes in his Zij-i Ilkhani.

The 12 year cycle, including Turkish / Mongolian translations of the animal names ( known as sanawat-e turki سنوات ترکی ,) remained in use for chronology, historiography, and bureaucratic purposes in the Persian and Turkish speaking world from Asia Minor to India and Mongolia throughout the Medieval and Early Modern periods.

In Iran it remained common in agricultural records and tax assessments until a 1925 law deprecated its use.