Today is the autumnal equinox, the official start of autumn at 2:43 PM

(Patria) - The autumnal equinox is today in the Northern Hemisphere, meaning most of the Earth's inhabitants will have exactly 12 hours of day and night, marking the official start of autumn, which will begin at 2:43 PM.

At the same time, spring will begin in the Southern Hemisphere.

According to Encyclopedia Britannica, the autumnal equinox is one of two days of the year – the other being the vernal equinox – when the Sun is directly above the equator, dividing the night and day into a period of exactly equal length.

While most people on Earth will have 12 hours of day and night, the sun will rise above the horizon for the first time in six months today at the South Pole.

At the same time, the last sunset will occur at the North Pole during the autumnal equinox, and the polar night will last until the vernal equinox in March.

Calendar autumn will last until December 21st at 10:20 AM.