Well, according to this article, today we'll be witness to the appearance of "the blue moon" although necessarily it does not always appear in that hue. So you might tell people that everything you did tonight you did it "once in a blue moon".
I, myself, was not aware that the infamous saying was born that way and it was interesting reading about it! And I still wonder about the influence a common mention of a word may have in a language!
Caroline van Riet (by Dutch origin) , who we had the pleasure of meeting in person at her lovely shop in Syracuse's old town Ortigia. Her work is incredible. You may check it here.