Four customs, four customs, four customs and four customs.

The day before the vernal equinox, autumnal equinox, summer solstice and winter solstice in 24 solar terms is technically called "leaving the sun". There are four such days in a year, so it is called "four days away from the sun"

"Yumen Jing" said: "Those who leave people, both yin and yang are divided into former dynasties." The vernal equinox and the autumnal equinox, even the summer solstice and the winter solstice. The day before means the day before. The day before the vernal equinox is called the Spring Festival. 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 the winter solstice is called water separation. On the "yellow calendar", the words "leave Japan at four o'clock, don't use it for major events" must be written. This is a day that is generally avoided when choosing a day.