Answer:
Equinox.
Explanation:
It is Equinox because Equinox is defined as the time when the sun rays passes through the Earth's equator. This happen twice in the year around 21 March and 23 September. It is the time when the center of the sun is directly above the equator.
This normally occur when the Earth axis is either tilted toward or away from the sun which lead to equal amount of daylight and darkness.
