Our early ancestors were deeply aware of changes in the seasons, and changes in the heavens above them.
As the days shortened, the harvest wound down. The fields were nearly empty, because the crops had been plucked and stored for the coming winter. As the autumn equinox approached, the ancients celebrated the changing seasons and gave thanks for the harvest.
Each equinox signals a balance between dark and light, an equal amount of day and night. While our ancestors celebrated the gifts of the earth, they also accepted that the time of light was ending. They had stores of food to eat, but the crops were brown and going dormant. Warmth was behind them, and long days of cold ahead.
During Medieval times, The Christian Church replaced earlier Pagan solstices and equinox celebrations with Christianized observances. Replacing the fall equinox is Michaelmas, the feast of the Archangel Michael, on September 29. His feast was celebrated with a traditional well-fattened goose which had fed well on the stubble of the fields after the harvest. In many places, a there was also a tradition of special large loaves of bread made only for that day. It was a time for beginning new leases, rendering accounts and paying the annual dues.
In 2008, the autumnal equinox occurs on September 22, at 3:44 PM (15:44)