Fortune-telling, four evils and four blessings.

This is a term used in fortune telling and auspicious days, such as the four wonders and the four broken moons.

For example, beginning of spring, Changsha, beginning of autumn and beginning of winter were called "Four Departures from Japan" the day before.

The day before the vernal equinox, summer solstice, autumn equinox and winter solstice is called "four unique days".

Generally speaking, "four times, four times, don't use big things", that is to say, there are many disadvantages in doing things in these eight days.

For reference.