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夏至是一年中日照时间最长的一天,冬至则是最短的一天;当然,全天的长度是不变的。夏至是怎么一回事夏至是二十四节气中最早被确定的一个节气。公元前七世纪,我们的祖先用土圭测日影,确定了每年的6月21日或22日为夏至。古人是这样解释夏至的:“日北至,日长之至,日影短至,故曰夏至。至者,极也。”夏至这天,太阳直射地面的位置到达一年的最北端,几乎直射北纬23°26′的北回归线,北半球的白昼达最长,且越往北白昼越长。例如,海南的海口市这一天的日长13小时多一点,杭州市为14小时,北京约15小时,而黑龙江的漠河甚至可达19个小时。当
The summer solstice is the longest day of the year in the sunshine, while the winter solstice is the shortest day; of course, the length of the day is constant. The summer solstice is one thing The summer solstice is the earliest year of twenty-four solar terms have been identified. In the seventh century bc, our ancestors used the earth to measure the sun and determined the annual solstice on June 21 or 22. The ancients interpreted the summer solstice as follows: “From the north to the east, the shortest Japanese shadow, so the summer solstice. Therefore, the extreme.” "The solstice the day, the sun’s direct ground location reached the northernmost point of the year Almost straight to the Tropic of Cancer at latitude 23 ° 26’N, with the longest day in the northern hemisphere and the longer the daylight goes to the north. For example, Haikou City, Hainan day longer than 13 hours a little bit, Hangzhou, 14 hours, Beijing, about 15 hours, while the Mohe Heilongjiang even up to 19 hours. when