Is each solar term only one day or only half a month?

There are only one day in each of the fourteen solar terms.

Each of the 24 solar terms corresponds to a certain position reached by the sun every time it moves 15 on the ecliptic. The twenty-four solar terms are divided into 12 solar terms and 12 solar terms, which correspond to each other one by one. The twenty-four solar terms reflect the annual apparent motion of the sun, so their dates are relatively fixed in the Gregorian calendar. The solar terms in the first half of the year are on the 6th, the solar terms in the second half of the year are on the 8th and the solar terms are on the 23rd, with a difference of less than 1 ~ 2 days.