When is the longest and shortest day?

The solstice day in summer is the longest and the solstice day in winter is the shortest. The summer solstice falls on June 2 1 or 22 every year. On the day of summer solstice, the direct position of the sun on the ground reaches the northernmost point of the year, almost directly to the Tropic of Cancer, and the daytime in the northern hemisphere is the longest, and the farther north it is, the longer it is. This is the longest day of the year in the northern hemisphere. 65438+February 22nd is the "winter solstice" among the 24 solar terms. On the solstice of winter, the sun shines directly on the tropic of Capricorn, and the day is the shortest and the night is the longest in the northern hemisphere.

The solstice day in summer is the longest and the solstice day in winter is the shortest. The summer solstice falls on June 2 1 or 22 every year. On the day of summer solstice, the direct position of the sun on the ground reaches the northernmost point of the year, almost directly to the Tropic of Cancer, and the daytime in the northern hemisphere is the longest, and the farther north it is, the longer it is. It is the longest day in a year in the northern hemisphere, and it takes about fourteen hours from sunrise to sunset in the south of China. 65438+February 22nd is the "winter solstice" among the 24 solar terms. When the sun meridian reaches 270 degrees, the winter solstice solar terms begin. In winter solstice, the sun shines directly on the tropic of Capricorn, with the shortest day and the longest night in the northern hemisphere, and the cold days begin from winter solstice.

The winter solstice is a very important solar term, and it is also a traditional festival in China's lunar calendar. Up to now, there are still many places where the winter solstice festival is held. The winter solstice is commonly known as "Winter Festival", "Dragon Solstice Festival" and "Asian New Year Festival". As early as 2500 years ago, during the Spring and Autumn Period, China had determined the winter solstice by observing the sun through the soil return, which was the earliest of the 24 solar terms. There is no 10 hour from sunrise to sunset in most parts of southern China. From winter to the future, as the earth orbits the sun, the direct sunlight belt gradually moves northward, making the days in the northern hemisphere gradually longer and the nights gradually shorter. In winter solstice, although the height of the sun is the lowest and the sunshine time is the shortest, the heat absorbed by the ground is more than the heat lost. After the winter solstice, it begins to count to nine, and every nine days is a "nine". Before and after the "March 9th", the heat accumulated on the ground was the least, and the weather was the coldest. There is a folk proverb in China, "It's cold in three or nine days, but hot in three days".