Both the northern and southern hemispheres receive an equal amount of daytime and nighttime during the equinoxes of autumn and spring. The Autumnal Equinox occurs around September 22nd in the northern hemisphere and around March 20th in the southern hemisphere, while the Vernal Equinox occurs around March 20th in the northern hemisphere and around September 22nd in the southern hemisphere. During these times, the tilt of the Earth's axis is such that the Sun appears to be directly above the equator, resulting in approximately equal hours of daylight and darkness across both hemispheres.
The season's equinox during which both the northern and southern hemispheres receive an equal amount of daytime and nighttime is the autumnal equinox. This occurs around September 22nd or 23rd in the northern hemisphere and around March 20th or 21st in the southern hemisphere.
