1. The autumnal equinox is the sixteenth solar term of the twenty-four solar terms and the fourth solar term in autumn. Dou refers to You; the sun reaches 180° of the celestial longitude; the festival is held on September 22-24 every year in the Gregorian calendar. On the autumnal equinox, the sun shines almost directly at the Earth's equator, making days and nights the same length all over the world. Autumn Equinox, "fen" means "equal" or "half". In addition to referring to the equinox of day and night, it also means the equal division of autumn. After the autumnal equinox, the direct sunlight position moves southward, the days are shorter and the nights are longer in the northern hemisphere, the temperature difference between day and night increases, and the temperature drops day by day.

2. The Autumn Equinox is the traditional "Moon Sacrifice Festival", and the Mid-Autumn Festival evolved from the "Autumn Eve Moon Sacrifice Festival". On June 21, 2018, the State Council approved the establishment of the "Chinese Farmers' Harvest Festival" and agreed to establish the annual autumnal equinox as the "Chinese Farmers' Harvest Festival" starting from 2018.