Once in a Blue Moon
"Blue moon" appears to have been a colloquial expression long before it developed its calendrical senses. According to the Oxford English Dictionary, the first reference to a blue moon comes from a proverb recorded in 1528:
If they say the moon is blue,We must believe that it is true.
Saying the moon was blue was equivalent to saying the moon was made of green (or cream) cheese; it indicated an obvious absurdity. In the 19th century, the phrase until a blue moon developed, meaning "never." The phrase, once in a blue moon today has come to mean "every now and then" or "rarely"—whether it gained that meaning through association with the lunar event remains uncertain.
"Blue moon" appears to have been a colloquial expression long before it developed its calendrical senses. According to the Oxford English Dictionary, the first reference to a blue moon comes from a proverb recorded in 1528:
If they say the moon is blue,We must believe that it is true.
Saying the moon was blue was equivalent to saying the moon was made of green (or cream) cheese; it indicated an obvious absurdity. In the 19th century, the phrase until a blue moon developed, meaning "never." The phrase, once in a blue moon today has come to mean "every now and then" or "rarely"—whether it gained that meaning through association with the lunar event remains uncertain.
The most common explanation (by NASA and the American Heritage Dictionary) defines a "Blue Moon" as two full moons in a single month - this occurs about every 2-1/2 years on average.
This month (12/09) it occured on Dec 2 and again on the 31st. But the weather is supposed to be rainy - not sure if we'll see it or not!