Question

Why are days and nights equal all over the world on 21st march and 23rd september?

Answer 1

Explanation:

because of the sun's path as seen from the equatorial region. The day is called “Equinox,” sometimes translated as “equal night.” The sun is in the sky for approximately 12 hours from the equator to higher latitude

Answer 2

On 21st March and September 23rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights