Is the zodiac counted according to the lunar calendar or beginning of spring?

The new Zodiac Year should begin in beginning of spring. According to reports, the method of taking beginning of spring as the standard of the zodiac began in the Shang and Zhou Dynasties. At present, the folklore used by the people, such as traditional numerology and divination, also takes the "beginning of spring" solar terms as the basis for calculating the zodiac. For example, if numerology depends on a person's date of birth, it must strictly start from spring.

Researchers pointed out that China used heavenly stems and earthly branches to record the year, month and day in ancient times. The zodiac, including the concept of twelve o'clock, is unique in the heavenly stems and earthly branches Chronology, which is a different system from the lunar calendar. The chronology of the trunk and branch is based on the sun, and heavenly stems and earthly branches alternately starts from beginning of spring every year. For example, the year of the horse is Wu Jianian, and the year of the sheep is B. According to the chronology of trunks and branches, the length of each year is about 365.25 days.