The origin of beginning of winter and beginning of winter in the 24 solar terms.

1. In the Spring and Autumn Period, people used soil gauge (vertical pole to measure the length of the shadow). The day when the sun shadow is the longest and the sun moves to the southernmost tip is the customized winter solstice.

2. In ancient China, beginning of winter was divided into three stages: "When the water is still, the ice begins; The second waiting place began to freeze; Waiting for the flood is a cockroach. " This solar water can already form ice; The land also began to freeze; In the third stage, pheasant refers to a big bird similar to pheasant, and pheasant is a big clam. After beginning of winter, big birds like pheasants were rare, but you can see big clams with similar lines and colors at the seaside. Therefore, the ancients thought that pheasants would become big clams in early winter.

3. The understanding of "beginning of winter" can't just stay in the sense of beginning of winter. Tracing back to the source, the ancient people's understanding of "establishment" is the same as that of modern people, both of which mean establishment and beginning. But the word "winter" is not so simple. In the ancient book "Twenty-four solar terms", the explanation of "winter" is: "Winter is the end, everything is harvested", which means that all crops in autumn are harvested, collected and put into storage, and animals have been hiding and hibernating. In a word, beginning of winter is to put everything away and avoid the cold in early winter.