Mid-Autumn Festival the ascendance and culmination of the Buddha's visit to heaven and for the latter, the acknowledgement of the cultivation season known as "Maha". The Mid-Autumn Festival is held on the 15th day of the eighth month in the Han calendar—essentially the night of a full moon—which falls near the Autumnal Equinox (on a day between September 8 and October 7 in the Gregorian calendar). In 2018, it fell on September 24. It will occur on these days in coming years: Mid-Autumn Festival The Mid-Autumn Festival is a harvest festival celebrated notably by the Chinese and Vietnamese people. The festival is
Equinox zero. Its latitude will not be exactly zero, since Earth is not exactly in the plane of the ecliptic. Its declination will not be exactly zero either. (The ecliptic is defined by the barycenter of Earth and the Moon combined.) The modern definition of equinox is the instants when the Sun's apparent geocentric longitude is 0° (northward equinox) or 180° (southward equinox). See the adjacent diagram. Because of the precession of the Earth's axis, the position of the vernal point on the celestial sphere changes over time, and the equatorial and the ecliptic coordinate systems change accordingly. Thus when specifying