Why does the 20 12 Lunar Snow Festival have a calendar of 65438+February 6th and a calendar of 65438+February 7th?

The time when the sun runs along the longitude of the Yellow River from zero 15 degrees is called "a solar term". It runs 360 degrees every year, and * * * experiences 24 solar terms, twice a month. Among them, the first solar term of each month is "solar term", that is, beginning of spring, Jingzhe, Qingming, Changxia, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter, Heavy Snow, Xiaohan, etc. 12 solar terms; The second solar term of each month is "Zhongqi", that is, there are 12 solar terms such as rain, vernal equinox, Grain Rain, Xiaoman, summer solstice, summer heat, summer heat, autumn equinox, first frost, light snow, winter solstice and great cold. "Solar term" and "neutral qi" appear alternately, each lasting 15 days. Now people have called "solar terms" and "neutral gas" solar terms.

Twenty-four solar terms reflect the apparent movement of the sun in one year, so the dates of solar terms are basically fixed in the current Gregorian calendar, with the first half of the year being 6 days and 2 1, and the second half being 8 days and 23 days, with a difference of 1 ~ 2 days.

Solar terms are more fixed than qi. . . The heavy snow on February 7, 65438 is a solar term, and it is no exception. . .

But there will be a difference of 1 ~ 2 days. . . For example, many years in 190 1 year, 1902 and 1979. . . The heavy snow is 65438+February 8. . .

The year around 1986 is 65438+February 7th. . .

Until 20 12 and 20 16, until 2048, the days of heavy snow appeared on 65438+February 6. . .