Full moon 29 or 30 days long. A full moon is often thought of as an event of a full night's duration. This is somewhat misleading because its phase seen from Earth continuously waxes or wanes (though much too slowly to notice in real time with the naked eye). Its maximum illumination occurs at the moment waxing has stopped. For any given location, about half of these maximum full moons may be visible, while the other half occurs during the day, when the full moon is below the horizon. Many almanacs list full moons not only by date, but also by their
Equinox equinoxes shift through the constellations as follows (expressed in astronomical year numbering when the year 0 = 1 BC, −1 = 2 BC, etc.): The equinoxes are sometimes regarded as the start of spring and autumn. A number of traditional harvest festivals are celebrated on the date of the equinoxes. Observations of the equinox are frequently used in online debates between flat-earth conspiracy proponents and those who support the generally accepted heliocentric globe model. Wolfie6020, a well-known flat-earth debunker on YouTube, has a semi-annual Equinox Challenge with prizes available to any flat-earther who can show a functioning flat-earth model that