What is the horoscope based on, such as knowing the year, month and day. How to calculate.

The eight characters are actually another way of saying the four pillars of Zhouyi. Four pillars refer to the time when a person was born, that is, year, month, day and hour. When people use "heavenly stem" and "earthly branch" to represent year, month, day and hour respectively, such as Jiazi Year, Shen Bingyue, Xin Ugly Day and Renyin Time. In the eight characters, the annual and daily branches are continuous and true; The branch of month and time is calculated according to the branch of year and day.

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