What are the two solar terms in September in the solar calendar?

There are two solar terms in September in the solar calendar: the Millennium and the autumnal equinox.

The Millennium is 15 of the "24 solar terms" and the third solar term in autumn, which falls on September 7-9 of the Gregorian calendar. "White dew" is an important solar term reflecting the growth of cold in nature. As the weather turns cold, it is still hot in sunny days, but as soon as the sun sets, the temperature drops rapidly and the temperature difference between day and night widens.

The autumnal equinox is the sixteenth solar term among the twenty-four solar terms and the fourth solar term in autumn. Celebrated on September 22-24 of the Gregorian calendar every year. On the day of the autumnal equinox, the sun shines almost directly on the equator of the earth, and the length of day and night is equal all over the world. The autumnal equinox means "equally divided" and "equally divided", which means equally dividing autumn except day and night. After the autumnal equinox, the position of direct sunlight moves south, and the days in the northern hemisphere become shorter, the nights become longer, the temperature difference between day and night increases, and the temperature drops day by day.