And on a certain day in winter, the shadow of the sun was the longest and the daylight the shortest, "the time when the moon grows." This was the winter solstice. The summer and winter solstices are actually due to the earth's spinning one revolution around the sun.
夏至冬至，其實是因地球公轉太陽一圈時，隨著每個定點不同，太陽直射地球的角度也會不同。