What happens to the ancient calendar during the winter and summer solstice?

Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.

Explanation:

this protocol provides a detailed procedure for nucleoprotein extraction from cultured cells and tissues in an efficient manner.