Full moon is called a blue moon. The term "blue moon" used in this sense may date to as early as the 16th century, but it became well known in the United States due to the "Farmers' Almanac" (published since 1818). According to the "Farmers' Almanac", a "blue moon" is the third full moon in any period between either solstice and equinox, or between equinox and solstice, (calculated using the mean tropical year), which contains four full moons. These seasons are equal in length, unlike the astronomical ones, which vary in length depending on the Earth's speed in its elliptical orbit round
The Equinox The Equinox The Equinox (subtitle: "The Review of Scientific Illuminism") is a series of publications in book form that serves as the official organ of the A∴A∴, a magical order founded by Aleister Crowley (although material is often of import to its sister organization, Ordo Templi Orientis). Begun in 1909, it mainly features articles about occultism and magick, while several issues also contain poetry, fiction, plays, artwork, and biographies. The last issue was published in 1998. "The Equinox" appeared semianually from the years 1909 through 1913. Volume II was never published, and vol. III:1 was the last in the regular