Full moon and the names "harvest moon" and "hunter's moon" for the full moons of autumn. The "harvest moon" and "hunter's moon" are traditional terms for the full moons occurring during late summer and in the autumn, in the northern hemisphere usually in September and October respectively. The "harvest moon" is the full moon closest to the autumnal equinox (22 or 23 September), coming anywhere from two weeks before to two weeks after that date. The "hunter's moon" is the full moon following it. The names are recorded from the early 18th century. The "Oxford English Dictionary" entry for "harvest moon" cites
Equinox Equinox An equinox is commonly regarded as the instant of time when the plane (extended indefinitely in all directions) of Earth's equator passes through the center of the Sun. This occurs twice each year: around 21 March and 22–23 September. In other words, it is the moment at which the center of the visible Sun is directly above the Equator. In the northern hemisphere, the equinox in March is called the Vernal or Spring Equinox; the September equinox is called the Autumnal or Fall Equinox. However, because the Moon (and to a lesser extent the other planets) cause the motion