"The Bailu geese belong to the geese, and the autumn equinox is fragrant with osmanthus." What does this sentence mean?

It means that in another year, it is the Millennium season, the swallows are back, and the geese are back; By the autumn equinox, osmanthus is ripe and fragrant. According to the experience of farmers, some poems mentioned in "Twenty-four solar term song" are: Spring rain shakes the valley and spring, summer is full and summer is hot; Autumn, autumn frost, winter snow, winter cold; There is no change in the two festivals every month, with a maximum difference of one or two days; Six in the first half of the year

Twenty-one, the second half of the year is August 23rd; The dates of the two festivals are fixed every month, with a difference of at most one or two.