In ancient times, the Jade Emperor in heaven called the five kings of fire, water and soil in Jin Mu, the underworld, to heaven to discuss their respective responsibilities for 365 days a year. Jin Mu's four heavenly kings of fire, water and fire arrived here on time. The local king was drunk in bed because of drinking. The Jade Emperor waited for a long time, but the local king never came. Therefore, the four seasons of the year are divided into spring, summer, autumn and winter, with Wang Mu in charge of spring, Fire King in charge of summer, Jin Wang in charge of autumn and aqua regia in charge of winter. Because the four heavenly kings have different personalities, the four seasons are different.
The jade emperor just finished distributing it when Wang Gang arrived. He clamored for an equal share of management. But the agreement that has been reached cannot be overturned. So the Jade Emperor came up with a way: in the four seasons managed by each king, 18 days were set aside for the local king to manage, and the four seasons totaled 72 days. In other seasons, it only saves 72 days. At this point, the local king agreed, saying that in the three, six, nine and twelve months of the four seasons, eighteen days were set aside to manage the local king. No one is allowed to take it.
Since then, the almanac records "the day when the king of the earth used things."