二十四节气中有八节非常重要,即立春、立夏、立秋、立冬、春分、夏至、秋分、冬至,确定了这八个节气,就等于确定了季始和季中。没有任何科学设备的古人,最先观察到的会是什么呢?没错,就是夏至和冬至。夏至这天北半球白昼时间最长,反之,冬至则是黑夜时间最长,如此特别的两天,自然最容易被察觉到。这两天在中国古代也被统称为“日至”。有关节气的最早文献记录是《尚书·尧典》。 Twenty-four solar terms in eight sections is very important, namely, the beginning of spring, the beginning of the summer, the beginning of autumn, winter, spring equinox, summer solstice, autumn equinox, the winter solstice, to determine the eight solar terms, is equivalent to determining the beginning of the season and the season. What did the first observation of an ancients without any scientific equipment? Yes, the summer solstice and the winter solstice. Summer solstice this day the longest time in the northern hemisphere, on the contrary, the winter solstice is the longest night, so special two days, nature is most likely to be detected. These two days were also collectively referred to as “date to date” in ancient China. The earliest documentation of solar terms is “Shang Yao Dian Dian”.