Which solar term starts to count as nine?

Count the solstice solar terms after beginning of winter.

China has been in cold weather for several years since the winter of November. Astronomical experts say that the Ninth Five-Year Plan is a more applicable solar term in northern China, especially in the middle and lower reaches of the Yellow River. From the day of winter solstice, it entered the "number nine", commonly known as "cross nine", and then every nine days as a unit, called "nine". After nine "nines", it happens to be 8 1 day, that is, "nine out", and then spring blossoms.

Because the process of "counting nine" is the process that the cold pole turns warm and the cold disappears and warms up, people often call this 998 1 day "nine days" and "counting nine cold days". The first nine days of "Jiujiu" are called "Yijiu", the last nine days are called "Erjiu" and the last nine days are called "Jiujiu".