On the statement in the hexagram system of yarrow. . .

"Jumping at the age of five" is the fifth year, and it begins to add 1/4 days. The key to the combination of yin and yang is moistening. The tropical years of the sun are 365 and 1/4 days (currently, it is estimated to be 365.2422 days, but the ancient approximate method is only 1 1 minute). There is a problem of nourishing yourself (one day in four years, one day in the fifth year 1/4 days, one day in every century). "Cohesion" said: "Moisturize at the age of five; So hang up again. " The general idea is: since it will be moistened again in five years, I will "share another share" It can be seen that yarrow divination is a simulated astronomical calendar, which is more accurate than copper coins. General experts still use yarrow hexagrams.