Chiljeongsan (calendar system)
Every day, the King and crown prince discussed a native calendar system with Jeong Cho and other officials at the Ganuidae royal observatory – A record of August 11, 1433, from the Sejong Sillok Chiljeongsan is the Korean native calendar system created in 1443, the 15th year of King Sejong’s reign, during Joseon. Chiljeong in…