A Blue Moon can be the second full moon in a month. Or it can be the third of four full moons in a season. The full moon of August 20-21, 2013 will be considered a Blue Moon.
A Blue Moon can be the second full moon in a month. Or it can be the third of four full moons in a season. The full moon of August 20-21, 2013 will be considered a Blue Moon.