Blue Moon Clarification

There are actually two definitions of a Blue Moon. The most modern, widely known definition is -- "A second full moon appearing in a single month". This meaning came into being when someone made a mistake and misinterpreted the meaning from The Maine Farmer's Almanac, in an article from Sky and Telescope, back in 1946. The Maine Farmer's Almanac, dating back to the early 19th century, states that a Blue Moon is -- "The third full moon in a season with four". From a May 1999 article in Sky & Telescope magazine: "A 53-year-old mistake in Sky & Telescope changed pop culture and the English language in unexpected ways"...by introducing the 'two Full Moons in a month' definition of a Blue Moon.

So, is the meaning I use here on my site incorrect then? No. The 'second Full Moon in a month' definition has been used for decades. People will continue to use it, and I personally like this definition better. Sky & Telescope wrote in May 1999: "With two decades of popular usage behind it, the 'second Full Moon in a month' (mis)interpretation is like a genie that can't be forced back into its bottle."

I have received emails about how I need to change the definition of a Blue Moon, as I have it here on my site. I will not change it. I will continue to use the "second Full Moon appearing in a single month" definition. I see no reason why I should have to change it, but I have added this little note as a bit of a 'disclaimer'. This way, people can find out the whole story of Blue Moons, and people will stop emailing me about how I am wrong and/or misinformed.