Which day is the longest and shortest in a year?

The longest night in Capricorn is the winter solstice on February 2 1 day, and the shortest night in Capricorn is the summer solstice on June 2 1 day. The solstice in winter is the extreme point of direct sunlight spreading to the south. From winter to the sun, the sun shines directly on the tropic of Capricorn, and the sun is most inclined to the northern hemisphere, and the elevation angle of the sun is the smallest. In all parts of the northern hemisphere, the days are the shortest and the nights are the longest.

The summer solstice is the culmination of the sun's northward movement. On this day, the sun shines directly on the Tropic of Cancer, and then the point of direct sunlight moves south. On the day of summer solstice, the height of the noon sun is the highest in all parts of the northern hemisphere north of the Tropic of Cancer, and the daytime reaches the longest in a year. After the summer solstice, the height of the sun decreases day by day.

Extended data:

The summer solstice is the tenth of the twenty-four solar terms. The "Twenty-four solar terms" were originally determined by the bucket handle direction of Beidou, which means noon, that is, the summer solstice. The current "twenty-four solar terms" are based on the degree of the solar ecliptic, that is, each solar term corresponds to a certain position reached by the earth every time it runs 15 on the ecliptic, and the summer solstice is when the sun runs at 90 degrees on the ecliptic.

The summer solstice is the northernmost day of the sun in a year, the limit of the sun's northward movement, and the longest day in the Tropic of Cancer and its northern region in the northern hemisphere. The higher the latitude, the longer the days. This is the "long day and short night effect" caused by the tilt of the earth's rotation axis, and the closer it is to two levels, the more obvious it is.

On the day of the summer solstice, except the south pole of the Antarctic circle and the polar night area, the sunrise direction in all parts of the earth starts from the northeast and sets in the northwest. On the day of the summer solstice, the area north of the Tropic of Cancer in the northern hemisphere got the most solar radiation, and after the summer solstice, the midday sun height angle began to decrease day by day.