Well actually the Harvest Moon was on October 5 and only comes once every three years.
Through most of the year, the moon rises each day about 50 minutes later than the day before. However, when the autumnal equinox approaches, the difference in rise times drops to about 25 to 30 minutes and even farther north, the difference is 10 to 15 minutes. As the Harvest Moon rises after sunset, this provides extra minutes of light each evening for farmers to work longer hours harvest their crops. (source)