Is beginning of autumn a fixed day?

The time in beginning of autumn is not fixed. When the sun reaches the longitude 135, it is the beginning of autumn, usually between August 7 and 9 in the Gregorian calendar. For example, beginning of autumn on August 8th, 20 19, and beginning of autumn on August 7th, 2020 and 202 1. Autumn is the harvest season. After beginning of autumn, the crops began to mature.

Beginning of autumn doesn't mean the hot weather is over. Beginning of autumn is still in a hot period, but it is not hot yet. The second solar term in autumn (summer) has come out, and the weather is still very hot in early autumn.

As the saying goes, "It's hot in dog days" and "It's hot after beginning of autumn", and there is at least one volt of hot weather after beginning of autumn. According to the calculation method of "three volts", "beginning of autumn" is often still in midsummer, that is to say, the heat is not over, and the real coolness usually comes after the Millennium solar terms. The cold-hot watershed in beginning of autumn is not a solar term.