What do you mean by four seasons and eight festivals?

Four seasons, spring, summer, autumn and winter.

These eight festivals refer to beginning of spring, Spring Equinox, Long Summer, Summer Solstice, beginning of autumn, Autumn Equinox, beginning of winter and Winter Solstice among the 24 solar terms.

As early as the Eastern Zhou Dynasty, the Spring and Autumn Period and the Warring States Period, our people had the concepts of south to Japan and north to Japan. Subsequently, people divided the year into 24 equal parts according to the natural phenomena such as the running position of the sun and the moon at the beginning and middle of the month, the weather and the growth of animals and plants. And give each equal part a proper noun, that is, twenty-four solar terms. By the end of the Warring States Period, solar terms had eight names: beginning of spring, Equinox, Long Summer, Summer Solstice, beginning of autumn, Equinox, beginning of winter and Winter Solstice. These eight solar terms are the most important of the 24 solar terms. These eight solar terms mark the change of seasons and clearly divide the four seasons of the year. Later, when the book Huai Nan Zi was published, the names of the 24 solar terms were exactly the same as those of the modern ones. The lunar calendar is neither a lunar calendar nor a solar calendar, but a combination of lunar and solar calendars. There is a leap month in the lunar calendar. If one year is counted from the first day of the first month to the New Year's Eve of the twelfth month, the number of days in the lunar calendar varies greatly (leap year is 13 months). The first day of the first lunar month often cannot correspond to the date of the solar calendar, let alone the lunar calendar (including the 24 solar terms). Only the Gregorian calendar and the trunk calendar basically correspond-because they all belong to the solar calendar! For example, every year on February 4th or 5th of Gregorian calendar is beginning of spring, which is the beginning of silver moon; April 4th or 5th every year is Tomb-Sweeping Day, which is the beginning of Chen Yue. Therefore, although the lunar calendar contains information about the 24 solar terms, it is wrong to think that the 24 solar terms should start from the first day of the first lunar month. Twenty-four solar terms began in beginning of spring, and that day in beginning of spring was the beginning of silver moon. It has been more than 3,000 years since the Spring Festival in beginning of spring. Zhao Zhi Heng, president of Tianjin Astronomical Society, said that in the early spring, Emperor Tiandi personally led three officials and nine ministers to the eastern suburbs to welcome the Spring Festival and pray for a bumper harvest. When you come back, you should reward the ministers and make a Bude order to show your kindness to the people. This kind of activity has influenced the common people and made it a national Spring Festival activity for generations.