What is "counting nine"?

You know, "March 9th is cold. Is the heat in the middle? After 1939, it was 1949, after 1949, it was 1959 ... until 1999. . This is called "counting nine". Count from the solstice in winter, one nine, two nine, three nine. Nine days is nine days. Counting nine times is "counting nine".

The Ninth Five-Year Plan means the degree of weather temperature change. 19, 29, out of reach; Walking on the ice on March 9 and April 9; Look at willows by the river in May and June, talk about rivers in July and September, talk about geese in August and September, and talk about scalpers in September and August. It is also said that 99 poplars landed and 19 apricot blossoms opened. 1999, farmers began to work in the fields. At that time, I cooked at home and ate outside.

This is written in the yellow calendar, such as 49 and 59, followed by 69, 79, 89 and 99.