When is the festival?

The day of the solar term means to reach this solar term one day. For example, the winter solstice is 65438+February 22nd, which means that 65438+February 22nd is the winter solstice season. Moreover, the specific time of the 24 solar terms every year is uncertain, but it is calculated according to the solar cycle.

Because the lunar calendar in China is a kind of "yin and yang calendar", which is based on the movement of the sun and the moon, it can't fully reflect the solar cycle. But China is an agricultural society, and agriculture needs a strict understanding of the movement of the sun, so farming is entirely based on the sun. Therefore, the "twenty-four solar terms" that reflect the solar cycle alone are added to the calendar as the standard for determining leap months.