1, the autumn equinox, is the sixteenth of the twenty-four solar terms, the time is generally for the annual calendar September 22 ~ 24 days. Autumn equinox on this day the sun reaches 180 ° longitude (the autumnal equinox), almost directly to the Earth's equator, the day and night around the globe is equal (not taking into account the atmospheric refraction of sunlight and morning and evening shadows). In ancient times, there was a "spring festival of the sun, autumn moon festival" folk activities, the autumn equinox was the traditional "moon festival" (Mid-Autumn Festival), Mid-Autumn Festival evolved from the autumn eve moon festival.

2, after the autumnal equinox, the sun continues to move from the equator to the southern hemisphere, the northern hemisphere began to short days and long nights, that is, within a day day day began to be shorter than night; the southern hemisphere on the contrary. Therefore, the fall equinox is also known as the descending equinox. At the north and south poles, the sun is on the horizon for the entire day of the autumnal equinox. Thereafter, as the sun's point of direct sunlight continues to move south, near the North Pole began a six-month polar night, the range gradually expanding and then shrinking; near the South Pole began a six-month polar day, the range gradually expanding and then shrinking.

3, June 21, 2018, the State Council on agreed to set up the "Chinese Farmers' Harvest Festival" approved the release of the reply, agreed that since 2018, will be set up every year for the autumn equinox as the "Chinese Farmers' Harvest Festival", the festival activities are mainly cultural and artistic The main activities of the festival are cultural and artistic performances and agricultural competitions.