why is it called a harvest moon

The term "Harvest Moon" refers to the full moon that occurs closest to the autumnal equinox, traditionally marking the time for gathering crops. It is called the Harvest Moon because farmers historically depended on the bright full moonlight to work late into the evening during harvest time. The moon rises soon after sunset for several nights in a row around this time, providing extended illumination that helped farmers bring in their crops after sunset, before artificial lighting was available. This name and tradition date back to Native American folklore and early agricultural societies.