There are four departures and four unique days. When is the four-off four-off?

The day before the vernal equinox, autumnal equinox, summer solstice and winter solstice of the four solar terms is technically called "leaving the sun". There are four such days throughout the year, so it is called "leaving the day".

"Yumen Jing" said: "Those who leave, Yin and Yang divide the day before yesterday." There are vernal equinox and autumnal equinox, and even summer solstice and winter solstice. The day before means the day before. Those who leave four times on the day before the vernal equinox are called Li Mu. The day before the summer solstice is called the fire prevention period; The day before the autumnal equinox is called the golden calendar; The day before winter is called "water separation". There must be four separation days in the "Yellow Calendar", which is the day before beginning of spring, Changxia, beginning of autumn and beginning of winter in the four solar terms, and it is called "four separation days". "Yumen Jing" says that "Si Li Ri is the day before Si Li Ri." In fact, it means "Wang Mushui in beginning of spring is absolutely unique, Wang Mu in long summer is absolutely unique, Jin Wang soil in beginning of autumn is absolutely unique, and Shui King Wang in beginning of winter is absolutely unique. Therefore, the first day is also unique. " If the wedding or engagement date you choose is a "unique day", there is absolutely nothing to envy, so be sure to check it carefully on the calendar! Metaphysics says that four o'clock from the sun and four o'clock from the sun are the time when the four seasons intersect and the four seasons transfer the chaos of Yin and Yang. This reminds me of the research on chaos mechanism in the frontier science and technology field in recent years, and thinks that when the system reaches a certain critical value, the phenomenon of order and chaos will appear between the systems. Is there any connection between the two? In the culture of choosing dates, there are eight days in a year that you don't have to consider. You can never choose.