"The autumnal equinox is upon us: On Saturday, September 22, both the Northern and Southern hemispheres will experience an equal amount of daylight. For those of us in the Northern Hemisphere, it marks the beginning of fall, with daylight hours continuing to shorten until the winter solstice in December. For those south of the equator, it’s the beginning of spring. Google is celebrating it with a Google Doodle of a falling leaf.
Technically speaking, the equinox occurs when the sun is directly in line with the equator. This will happen at 9:54 pm Eastern time on Saturday.
Below is a short scientific guide to the most equal night of the season."