equent modifications of the astronomical systems to improve almanac accuracy. One of the reasons why Li&#250; X&#299;n deliberately mystified the almanac was to provide evidence that the western Han emperor was about to lose the mandate of heaven and would be replaced by W&#225;ng M&#462;ng (王莽), who later became the founder of the Xin dynasty. Unfortunately, the pursue of <i>sh&#224;ngyu&#225;n</i> was followed by subsequent almanac makers, and more conditions were added to the epoch. The term <i>sh&#2