The Harvest Moon is the 10th full moon of the year, the first in autumn. The date of the Harvest Moon shifts due to the nature of the Gregorian calendar, but it is in September, close to the autumnal equinox. By the lunar calendar it is fixed on night of the 15th of the 8th month.

But why, you ask, is the Harvest Moon so called? Well, during the early autumn crops are being harvested, and at that time the Harvest Moon rises at exactly the same time as the sun sets. This gives farmers a longer length of continuous light to harvest by. Thus, it is the moon of the harvest.