The second full moon occurring within a calendar month is known as a ‘what’ Moon?
Blue moon "Blue Moon World Tour.". "Blue Moon of Kentucky" is a bluegrass standard, written in 1946 by Bill Monroe. In the 1998 paranormal romance fiction novel by Laurell K. Hamilton of the same name, "Blue Moon" refers to two full moons occurring within the same month. In the 2009 young adult fiction novel by Alyson Noël of the same name, "Blue Moon" refers to two full moons occurring within the same month and the same astrological sign. Note that if two full moons fall within the same astrological sign they will fall in different calendar months, and "vice versa". In the
Ecclesiastical full moon Ecclesiastical full moon An ecclesiastical full moon is formally the 14th day of the ecclesiastical lunar month (an ecclesiastical moon) in an ecclesiastical lunar calendar. The ecclesiastical lunar calendar spans the year with lunar months of 30 and 29 days which are intended to approximate the observed phases of the moon. Since a true synodic month has a length that can vary from about 29.27 to 29.83 days, the moment of astronomical opposition tends to be roughly 14.75 days after the previous conjunction of the sun and moon. The ecclesiastical full moons of the Gregorian lunar calendar tend to agree