What is the solar term on February 29th?

Explanation: eighteen. There is a twenty-nine in winter, which is a folk solar term. The beginning of winter on solstice and the day of 998 1 year are the end of cold. Folk songs include: Count to nine before counting to nine, 1929 Don't shoot. Three, nine, four, nine, walking on the ice. Look at the willows by the river. Seven or nine rivers open and eight or nine swallows come. Ninety-nine and nineteen, plowing cattle everywhere.

Source: Han's "Tai Xuan Tu": "There are six or nine Xuan, three or six strategies, two or nine instruments, and nine times out of ten Xuan?" Wang Fan's note: "If it's not true, just say it's true at 29, and the words are mysterious."