The time represented by the Zhen diagram is the March of the lunar calendar. In the acquired eight diagrams, the earth branch of Zhen is Mao, so Zhen also represents the year, month and day when the earth branch belongs to Mao. The ancient people's identification of geographical location was initially determined by sunrise and sunset, taking sunrise as the East, and then distinguishing the south, north and west. The ancient people believed that all things grew by the sun, which was the most important source of Yang between heaven and earth, and could break the darkness and evil of night. Because the beginning of the Zhen diagram was Yang, and the rest were all Yin. There was a phenomenon that Yang just began to rise and develop, just like in the morning When the sun rises at the beginning, the Zhen will be accepted as the east of the rising sun in the evolution of the gossip after tomorrow. Before and after the Spring Festival, the sunrise is just east, and during this period, the weather is gradually away from the winter cold, the climate is gradually warm, and all plants and things are revived and sprouted, showing a lively phenomenon. This is also the rejuvenation of wood gas value. Therefore, the five elements of the Zhen belong to wood.