When do the twenty-four solar terms occur?

The 24 solar terms belong to the lunar calendar, but they are all divided according to the position of the sun. That is, according to the position of the sun on the ecliptic, a year is divided into 24 equal parts. That is, the ecliptic is divided into 24 equal parts, each of which accounts for 15 degrees. Because the time required for the sun to pass through each bisection is almost equal, the Gregorian calendar dates of the 24 solar terms are roughly the same: the first half of the year is before the 6th, and 2 1.

So generally speaking, it should be once every 15 days and twice a month, but not necessarily, because there are only 360 days, and the remaining days should be accumulated by setting leap months.