Harvest Moon is a popular farming simulation video game series that was first released in 1996. The term 'Harvest Moon' refers to the full moon closest to the autumnal equinox, which typically occurs in September or October. The crossword solutions for the term 'Harvest Moon' are SEPT, with 4 letters, and OCT, with 3 letters. This reflects the fact that the Harvest Moon usually occurs in either September or October.