According to the theory of five elements, the soil grows vigorously in the last month of the four seasons. That is, March (Chen Yue), June (non-month), September (moon) and December (ugly month) of the lunar calendar. In spring, when the wood is there, the wood is in the soil. Born in spring, the core tablet of life is severely restrained and basically belongs to the weakest. In summer, fire is in season, and fire is born in soil. Born in summer, the soil can be born in the moon, and the soil is more prosperous.