Encyclopedia of India–China Cultural Contacts v1.c6.s1.t3.35

v1.c6.s1.t3.35

In the Gautama family, Gautama Siddhartha had made outstanding contributions to astronomy. According to the records in Volume 1 of *Kai Yuan Zhan Jing*, in Jing Yun second year (711), Emperor Ruizong of Tang, Gautama Siddhartha was ordered to hold the repair work for the armillary sphere which was built by Emperor Ruizong of Northern Wei Dynasty, which he completed in Xiantian second year (713 CE) of Emperor Xuanzong. *Old Book of Tang-Astronomical Log* recorded that Gautama Siddhartha was ordered to translate the Indian calendar Jiuzhi Calendar in Kaiyuan second year (718) of Emperor Xuanzong (refer to Article *Kai Yuan Zhan Jing*). According to textual research, Gautama Siddhartha was ordered to compile *Kai Yuan Zhan Jing* after February, Kaiyuan second year (714), and he completed the compilation before Kaiyuan 14^th Year (726). *Kai Yuan Zhan Jing* compiled by Gautama Siddhartha collected many astronomical data during ancient and mediaeval times in China. Additionally, the translation and Jiuzhi Calendar collected and recorded in Kai Yuan Zhan Jing are the Chinese Indian Calendar preserved till now.