Spring and winter equinox, like march 23 and september 23 have different length of days as changes in rotation and tilt in earth.
Explanation:
As farther you move from the equator the more extreme changes take place in the daylight. The length of the day becomes lesser and lesser and is limited by 5.5 months only. These charges are brought through the rotation of the earth on its axis and the season of the year.
The darkness can be for 11 months. As the autumn equinox starts on September 23. Thus the tilt is the reason why the summer days are much longer and shorter in winter. Also, the poles are far away from the tropics thus they receive less sunlight.
