Definition of

Equinox

Equinox
The time of the year when day and night are each 12 hours long and the Sun is at the midpoint of the sky.

This happens twice a year:
* Spring equinox
* Autumn (Fall) equinox

Equinox happens around March 21 and around September 21 each year.

Copyright © 2016 MathsIsFun.com