What are the 24 solar terms called? According to the lunar calendar, from what date to what date is a solar term?

24 solar terms is divided into lunar calendar or solar calendar: solar calendar.

Twenty-four solar terms are part of the traditional lunar calendar, which is essentially a solar calendar, and the general Gregorian calendar is also a solar calendar. The natural coincidence degree between them is high, but there is a fluctuation of 1-2 days.

The twenty-four solar terms are essentially 24 fixed positions of the sun's apparent motion on the ecliptic (the ecliptic is divided into 24 points, each of which is 15). Four of them are the most important: vernal equinox (longitude 0, day and night are equally divided), summer solstice (longitude 90, the shortest shadow and the longest day), autumn equinox (longitude 180, day and night are equally divided) and winter solstice (longitude 270, the longest shadow and the longest night).

After observing the bisection, you can calculate the rest of the solar terms. So the interval of each solar term is roughly 365/24= 15 days (in fact, the revolution of the earth is not uniform, so it is not a simple division). But solar terms are precise longitude, so solar terms are actually precise time, not a day. It just means that the solar term falls on a certain day, which is called the solar term.