Blue on New Year's Eve

On New Year’s Eve 1990, my wife and I attended a contra dance in Cleveland on a blue moon, which, by the newer definition, is the second full moon in the same month. The dance caller announced the blue moon between dances and said it would be the last blue moon on New Year’s Eve until some year that at the time seemed far in the future, which I assume is this year.
We get two full moons this month — the first fell on Dec. 2, at 2:30 a.m., and the second will appear on Dec. 31. The exact time of the full moon on New Year’s Eve is 2:13 p.m., but for viewing purposes the moon will look plenty full the night before and that night, and with Ohio’s cloud cover we have about equal chances of viewing the moon in the afternoon as at night.
Our blue moon falls 10 days after the winter solstice, when we officially, astronomically welcome winter at 12:47 p.m. Dec. 21. On that day, the Sun will reach a declination of 23 degrees 26 minutes south, its southernmost point in the sky, when the hours of day will be shortest and night longest. If that makes you cold, remember that summer begins in the Southern Hemisphere that day.
Blue moon, as I implied, has more than one definition, and our meaning, the second full moon in one month, is the newer definition, one that was created by mistake by “Sky and Telescope” in an article written by amateur astronomer James Hugh Pruett dated March 1946. S&T reports on its mistake and provides the traditional meaning in a 1999 issue and cites “Farmer’s Almanac” of Lewiston, Maine, as the source of the correct traditional definition. FA defined a blue moon as an extra full moon occurring in a season. One season normally had three full moons, and if a season had four full moons, the third full moon was a blue moon. The S&T article, which can be found online at, also explains that the almanac follows the tropical year, which runs from one winter solstice to the next, and goes into great detail about the calendar and why the third full moon is the blue moon. An article by “Farmer’s Almanac” explaining the blue moon can be found online at
I like to be technically correct with word usage, but I also think the newer definition is an acceptable usage that explains an unusual occurrence. We have no other simple term for blue moon, and it’s easy to keep track of the number of full moons in one month. Unless someone wants to coin a distinct word for the second full moon in the same month, as opposed to the third full moon in a season, I consider blue moon suitable. And once a term gets locked into common usage, it’s about as easy to dislodge it as it is to stop the Moon from rising, as noted in “Sky and  Telescope”:
“… widespread adoption of the second-full-Moon-in-a-month definition followed its use on the popular radio program StarDate on January 31, 1980. We examined this show’s script, authored by Deborah Byrd, and found that it contains a footnote not read on the air that cites Pruett’s 1946 article as the source for the information. Byrd now writes for the radio program Earth & Sky, whose Web site contains a note giving her perspective on this modern contribution to lunar folklore.
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. But that’s not necessarily a bad thing. Rather than argue over whether to celebrate the dawn of the new millennium on January 1st in 2000 or 2001, those with the sunniest outlooks will celebrate twice. Why not treat Blue Moons the same way, marking both the second full Moon in a calendar month and the third full Moon in a season with four?”

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