Twenty-four solar terms and monthly changes in trunk and branch

The division of years and months used in the four-column arrangement is also strictly in accordance with the solar terms, rather than the usual division of years and months in the lunar or solar calendar. This is the basic principle of four-column arrangement, which makes the four-column arrangement unaffected by calendar changes and maintains its accuracy. More importantly, it takes the tropic year as the chronological symbol, conforms to the rhythm of the four seasons and follows the causal relationship of the cycle of heaven, which are the theoretical basis of numerology.