September Equinox: Equinox—from Latin aequus “equal” and nox “night”—is the time of year where night and day are almost equally long. The September equinox occurs either on September 22, 23, or 24. It marks the first day of fall and is called autumnal (fall) equinox in the Northern Hemisphere. Harvest Moon: In many Native American cultures, Septemb...