Once in a blue moon

United States
May 31, 2007 1:28pm CST
We've all heard and/or used the expression. "Once in a blue moon", meaning once in a great long while. However, many of us don't know what that really means or where the expression comes from. A "blue moon" is a full moon that happens for the second time in a calendar month. Since full moons come around just every 30 days, it is quite rare when there are two in the same month. It has to be in a month with 31 days, and they have to be precisely on the 1st & 31st of that month. Tonight, May 31, will be the second full moon this month, and will thus be a blue moon. So if something unusal happens to you today, you can truly say that it happens only once in a blue moon.
4 people like this
4 responses
sadgirl_1958
@sadgirl_1958 (1088)
• United States
5 Jun 07
I did know where this expression came from actually. Unfortunately for me nothing of great significance happened! I had an argument with a good friend, so I would love to say that will only happen once in a blue moon!
1 person likes this
cher913
@cher913 (25782)
• Canada
31 May 07
it is so interesting where sayings come from. Sometimes "Reader's Digest" (a North American publication) features a piece on where certain sayings come from...it is sooo interesting! thanks for sharing this one!
1 person likes this
Ainsley Jo Phillips
@AJ1952Chats (2332)
• Anderson, Indiana
21 Feb 08
Of course, the genuine blue moon years are those that happen every few years where there are 13 full moons in the year instead of the usual 12. I've been interested in this phenomenon for several years now and will, someday, write a book about it.
gwendovere
@gwendovere (1279)
• United States
5 Aug 07
Wow! I've always adored this expression, but never knew what it really meant. I saw a pic once of a full moon that had been coloured blue & it was devestatingly beautiful.