The Autumnal Equinox signals the end of the summer months and the beginning of Fall. Almost without our notice, the days have been shortening since the Summer Solstice three months earlier. The Equinox is the point where night is the same length as day. After this point, the Sun will shine lower and lower on the horizon, the days will grow shorter and the nights longer, until the Winter Solstice in about three month's time. This year, 2011, the Autmnal Equinox wil occur and Fall will begin on Friday, September 23.