What do the last two sentences of the solar term Song mean? "The first half of the year is June 2 1 day, and the second half is August 23."

1, "The first half comes from June to February1day and the second half comes from August to 23rd": it means that the first half comes from June to June and the second half comes from July to June. In the first half of the year, 2 1 is a solar term every 6 days, and in the second half of the year, it is a solar term every 8 days and 23 days, with a general difference of one or two days.

2. Twenty-four solar terms are a supplementary calendar used to guide farming in ancient China, namely: beginning of spring, Rainwater, Creeping, Equinox, Qingming, Grain Rain, Long Summer, Xiaoman, Mangzhong, Summer Solstice, Slight Summer, Great Summer, beginning of autumn, Early Summer, White Dew, Autumn Equinox, Cold Dew, Early Frost, beginning of winter, Light Snow, Heavy Snow and Winter Solstice.

The four seasons and eight festivals are the skeleton of the twenty-four solar terms and calendar. The other 16 solar terms are branches or meat on the skeleton. Using branches or meat is a bridge between astronomical season and meteorological season.