The Autumn Equinox is the 16th of China's 24 solar terms and the fourth solar term of autumn. It means that day and night are equal and cold and heat are balanced. At this time, the sun shines directly on the equator, and day and night are equally divided. From the Autumn Equinox onward, daytime becomes increasingly shorter than nighttime, the temperature difference between day and night continues to increase, and the weather gradually turns cooler.