Song dynasty ***8 1 day or 90 days?

Jiujiu song is a traditional peasant ballad in China, and its alias "Jiujiu" or "Winter Jiujiu" is a folk solar term in winter in China. From the day after the winter solstice at the end of June 65438+February in Gregorian calendar, the weather will get warmer every 9 days until the 9th and 8th1day.

This song vividly records the changes of climate and phenology between the winter solstice and the vernal equinox, and also expresses some laws of agricultural activities.