September 22 marks the autumnal equinox – the beginning of fall or autumn, depending on where you grew up.

There are several ideas of autumn: there is the astronomical notion, the time when the sun is aligned over the equator, typically on the 22 or 23rd of September each year.  There is the meterological autumn, which is September 1 – November 30.

On this day, the period of day and night are the same length.