Shao Yong's Cosmic Cycle

Shao Yong's cosmic cycle is the eleventh century Chinese cosmological scheme the Song dynasty philosopher Shao Yong set out in his Huangji Jingshi (Supreme Principles Governing the World). It divides the life of the cosmos into one great cycle, a yuan, of 129,600 years, itself divided into twelve hui of 10,800 years, each hui into thirty yun of 360 years, and each yun into twelve shi of thirty years, a nested structure worked out from the numerology of the Yijing rather than from observed history. Shao Yong correlated the cycle's unfolding with his own before heaven arrangement of the Yijing's sixty four hexagrams, so that the rise, standing, decline and renewal of the cosmos could in principle be read from the hexagram sequence itself.