When is the length of Antarctic day and night equal?

1. When the sun shines directly on the equator, the length of day and night in the South Pole is equal. At the vernal equinox (March 2 1 or so), the direct point of the sun is at the equator (0).

The vernal equinox, one of the 24 solar terms, is the fourth solar term in spring. The solar calendar reaches 0, and festivals are held on March 20th or March 2nd1day of the Gregorian calendar every year. At the vernal equinox, the direct point of the sun is on the equator, and then the direct point of the sun continues to move northward, so the vernal equinox is also called the "ascending equinox". In ancient times, it was also called "Japan-China", "Day and Night" and "Mid-spring Moon".

The vernal equinox is an important solar term, which is of great significance in astronomy: the northern and southern hemispheres are equally divided day and night. In climate, it also has obvious characteristics. Since then, the direct position of the sun has continued to move from the equator to the northern hemisphere. The days in the northern hemisphere are getting longer and shorter, and the nights in the southern hemisphere are getting shorter and shorter.