Early autumn is cold and late autumn is hot. What do the proverbs mean in early autumn and late autumn?

"It's cold in beginning of autumn in the morning and hot in beginning of autumn at night" means that in a year, if the time in beginning of autumn is in the morning, the weather will get colder after beginning of autumn. If the time in beginning of autumn is at night, the weather will not get cold gradually after beginning of autumn, and it will continue to be hot for some time. There is another saying that if the season in beginning of autumn occurs in June of the lunar calendar, it can be regarded as early autumn, and if it occurs in July of the lunar calendar, it is naturally late autumn. "