The Autumn Equinox Day in 2019 is on Monday, September 23.

Equinox is not just a day when the sun is just above the horizon so much that day and night are even. On September 23, the sun will give the southern and northern hemispheres the same amount of light.

The autumn equinox is the moment when the Earth orbits exactly three-fourths of the way around the sun. Starting from this day the night will be longer than the day, gradually adding little by little until the Earth reaches the final point of its journey.

Google has created a doodle for the Autumn Equinox on which a smiling oak leaf is covered by a smiling Earth.