The Harvest Moon
It used to be called "The First Point of Aries", because it was located just inside the constellation Aries. However, due to precession the 'point' shifts over time.
During the autumn equinox, the full moon is commonly known as the Harvest Moon. It is the full moon that is closest to the autumnal equinox and traditionally provided extra light for farmers to harvest their crops late into the night.
The day when day and night are equally long is called an equinox. There are two equinoxes each year: the vernal equinox, which occurs around March 20 or 21, marking the beginning of spring in the Northern Hemisphere, and the autumnal equinox, occurring around September 22 or 23, signaling the start of autumn. During these times, the Earth's tilt is such that the sun is directly above the equator.
A big and orange moon is often referred to as a "harvest moon," a term that describes the full moon that occurs closest to the autumnal equinox. The moon can appear larger and have an orange hue due to its position in the sky and the angle at which its light passes through the Earth's atmosphere.
The sun appears to cross the celestial equator twice in the course of one year. The point in the sky where the sun appears to cross the celestial equator on its way south is called the Autumnal Equinox. The moment when it appears to be in that position is called the "Beginning of Fall" in the northern hemisphere. The point in the sky where the sun appears to cross the celestial equator on its way north is called the Vernal Equinox. The moment when it appears to be in that position is called the "Beginning of Spring" in the northern hemisphere.This happens at the equinox, which is around March 21 and September 21. (The date varies a day or so either way, depending on the cycle of leap years.)If you need to know exactly when this is, you can look that up on the US Naval Observatory's web site on the "Earth's Seasons" page (linked below).
The autumnal equinox.
It's called the Equinox, which happens biannually, one called Vernal Equinox (Spring), and one called Autumnal Equinox (Fall).
It used to be called "The First Point of Aries", because it was located just inside the constellation Aries. However, due to precession the 'point' shifts over time.
The first day of autumn is called the autumnal equinox.
Autumnal equinox
The length of day and night is equal at the Vernal and Autumnal equinox.
A second harvest is sometimes called a full moon harvest. This may occur if harvest time is close to the autumnal equinox.
Its called an equinox. There is the Spring and the Autumnal Equinox. This occurs when the Sun is directly above the equator. It means equal day, where the days and nights are of the same length. See the related link for more information.
It is called the Autumnal Equinox. It is the day of equal daylight and darkness following the Summer Solstice. The first day of Spring is called the Vernal Equinox. It is the day of equal daylight and darkness following the Winter Solstice.
The Sun is directly overhead the equator two times per year, known as the Equinoxes. In the northern hemisphere, the Spring Equinox occurs on March 20 and the Fall Equinox occurs on September 22.
It is called an equinox. In the spring it is known as the Vernal Equinox while in the autumn it is known as the Autumnal Equinox. Both take place around the 21st of March/September, but the date varies slightly each year.
The length of day and night is equal at the Vernal and Autumnal equinox.