What is the changing law of the length of day and night?

The change law of the length of day and night is:

1, vernal equinox points to summer solstice:

In the northern hemisphere, the days are long and the nights are short. The days are getting longer and the nights are getting shorter. The length of day and night is equal at the vernal equinox, and the length of day and night is the longest and shortest at the summer solstice. Extreme days appear in the Arctic, and the scope of extreme days is expanding. The days are short and the nights are long in the southern hemisphere. The nights get longer and the days get shorter. At the vernal equinox, the length of day and night is equal, and the day is the longest and shortest in summer solstice. Extreme night appears in Antarctica, and the range of extreme night is expanding.

2. Summer solstice points to the autumnal equinox:

In the northern hemisphere, the days are long, the nights are short, the days are getting shorter and the nights are getting longer. The autumnal equinox is equal in length, and the longest day and the shortest night are on the summer solstice. Extreme days appear in the Arctic, and the range of extreme days is shrinking. The days are short and the nights are long in the southern hemisphere. In addition, the nights are shorter and the days are longer. The day of the autumnal equinox is as long as the night, and the day of the summer solstice is the longest and shortest. There is an extreme night in Antarctica, and the range of extreme night is shrinking.

3. The autumnal equinox points to the winter solstice:

In the northern hemisphere, the days are short and the nights are long. The days are getting shorter and the nights are getting longer. The day of the autumnal equinox is as long as the night, and the winter solstice has the longest day and the shortest night. The extreme night appears in the Arctic, and its scope is expanding. The days are long and the nights are short in the southern hemisphere. The nights get shorter and the days get longer. The autumnal equinox is equal in length, and the daytime is the longest and shortest in winter solstice. Extreme day appears in Antarctica, and the range of extreme night is expanding.

4. The winter solstice points to vernal equinox:

In the northern hemisphere, the days are short and the nights are long, the days are getting longer and the nights are getting shorter and shorter. At the vernal equinox, the length of day and night is equal, with the longest day and the shortest night in winter solstice. Extreme night appears in the North Pole, and the range of extreme night is shrinking. The days are long and the nights are short in the southern hemisphere. The nights are getting longer and the days are getting shorter and shorter. At the vernal equinox, the length of day and night is equal, and the daytime is the longest and shortest in winter solstice. Extreme day appears in Antarctica, and the range of extreme night is shrinking.