Explain the geographical importance of March 21, June 21, September 23, and December 22.

Geographical importance of March 21, June 21, September 23 and December 22 are given below:

* 21 March: This is the day when sun rays are vertically over the equator and all over the world the days and nights are equal on 21^st March.

*21 June: It is very important day for our planet. 21 June is known as Summer Solstice in the Northern Hemisphere. On this day Northern Hemisphere experiences its longest day and shortest night. This day is beginning of summer in the northern hemisphere and winter in the southern hemisphere.

*23 September: On 23 September sun rays are vertically over the equator and all over the world the days and nights are equal on this day.

*22 December: 22 December is known as Winter Solstice in the Northern Hemisphere. On this day the Northern Hemisphere experiences its shortest day and longest night.