The name and date of geographical solar terms, the location of the direct point of the sun, the length of day and night, the northern hemisphere

The four seasons cycle in spring, summer, autumn and winter because of the angle between the central axis of the earth's revolution around the sun and the ecliptic plane (the orbit of the earth's revolution around the sun)

(66 34'). For the northern hemisphere of the earth, during the winter solstice, the day time is the shortest and the night time is the longest; In the future, the time of day will increase day by day (often) and the time of night will decrease day by day;

In the summer solstice, the day is the longest and the night is the shortest. In the future, the days will be shorter and the nights will be longer.

During the vernal equinox and autumn equinox, the time of day and night is almost equal. The winter solstice is 65438+February 2 1 and 2, and the summer solstice is June 2 1 ~ 23.

Day.

The vernal equinox is within one or two days around March 20th in the solar calendar, and the autumnal equinox is within one or two days around September 22nd in the solar calendar.