Where did the idiom " once in a blue moon " came from?

Answer 1

Meaning

A very rare event.

Origin

A blue moon was originally cited as something impossible and later came to mean unlikely. There are rare examples of the moon actually appearing blue, after volcanic eruptions or unusual weather conditions. Another possible derivation is from The Maine Farmers' Almanac. When there were two full moons in a calendar month the first was printed in red, the second in blue.

Answer 2

Once in a blue moon

Meaning: To happen only on rare occasions.

Origin: Two full moons in the same month are extremely rare, though they do happen. A second full moon has come to be called a blue moon. This is apparently because the Maine Farmers Almanac used to list the date of first moon in red text, and the second moon in blue.
Thanks to Charlie Moreland

The first published use of the phrase was in the 1600's, "Rede Me and Be Not Wrothe" and English poem by Roy and Barlow that in part says "If they say the moon is blue, we must believe it is true" the "they" in this poem referring to English nobility.

Also, the moon on rare occasions actually appears to be blue. For example, if there was a volcanic eruption somewhere, suspended ashes in the atmosphere can make the moon appear bluish.

Thanks to Rob Lent

Answer 3

A "blue" moon means two full moons in one month - a rare occurrance.

Answer 4

elvis

Answer 5

shakespeare's play.