A Harvest Moon Will Appear on Friday the 13th. This will be the first full moon on the famously superstitious day since October 2000. Afterwards, another one isn't scheduled until August 2049. For most of the U.S., the lunar phenomenon will appear after sunset this Friday. . For the East Coast, it will happen just after midnight at around 12:30 AM. Harvest Moons occur when the summer season begins to turn into fall. . This period is known as the autumnal equinox, which is usually around the end of