AUGUST 20th 2013 - BLUE MOON
So apparently, there is another sort of Blue Moon that occurs, one far more rare than the kind we know of. A typical Blue Moon is when two full moons occur in the same calendar month. The other type of Blue Moon happens when four full moons occur in one season instead of the normal three. A season is defined by the time between a solstice and an equinox (and vice versa) usually holding three full moons.
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