What is the harvest moon?

Harvest moon
   Harvest Moon is the full moon that occurs nearest the date of the autumnal equinox, September 22. Since this is harvest time, the name harvest moon has become general. At this time of year the moon is traveling at the least possible angle with the ecliptic, and rises at about the same time on several successive nights, and shines with unusual brilliance. While the harvest moon has often been the inspiration of poet and painter, it also serves the practical purpose of furnishing the agriculturist with light strong enough to work by at the season when time is precious.