Why is the winter solstice the most important solar term in a year?

Let's talk about its origin first. The winter solstice is the earliest of the 24 solar terms. The earliest record of the winter solstice was in the late Shang Dynasty and the early Zhou Dynasty. Duke Zhou measured the shadow with the method of earth rules. "The table of a tree is eight feet, but on the summer solstice, this scene is five inches long;" On the solstice of winter, this scene is one foot, three feet and five inches long. " The ancients said: When the cathode arrived, the yang began to grow, the sun went south, the day was short and the shadow was long, so it was called "winter solstice day".

That is to say, from this day on, Yin Qi flourished and declined, while Yang Qi became longer and longer. Since then, the day has become longer and longer, and the cycle of the next year has begun. This is a good day. Since then, this festival has been used for more than 3000 years.

In ancient times, the winter solstice can also be used to predict the future weather:

There is "the winter solstice is dark, and the New Year is thin; The winter solstice is sparse, and the New Year is black. This is a direct forecast of the weather in the New Year: if the solstice in winter is cloudy, then the New Year is sunny.

On the contrary, if the winter solstice is sunny, it may be cloudy or even snowy during the New Year. The unbelieving partners can use the weather from winter to Sunday this year and the weather in New Year next year to prove it.