The Autumnal Equinox signals the end of the summer months and the beginning of winter. At this time of year, days have been shortening since the Summer Solstice some three months earlier, and the Equinox is the point where nights reach the same length as days. After this point, the Sun will shine lower and lower on the horizon until the Winter Solstice in about three months' time.
Preparation for my own small celebration to mark the changing light and the gift of a day of balance are on the list of to-do's this day. Usually I mark the day on the 21st as it is easier for me to remember but this year I have decided to go with the stars so tomorrow is set aside for thought, thanks and treats:0) More of that later. For now here is a website that you might enjoy if you ever look up to the stars and wonder.