Irish novelist Margaret Wolfe Hungerford may be best remembered today for this phrase.
But, as Wikipedia documents, Hungerford was quite a prolific and successful author in the late 1800s.
In the United States, Hungerford's works were issued under the pen name "The Duchess."
Thus, as several of the Usual Suspects attest, today is The Duchess Who Wasn't Day -- because Mrs. Hungerford wasn't actually a duchess. Get it?
Zany Holidays says we celebrate today as The Duchess Who Wasn't Day because it is the anniversary of Mrs. Hungerford's birth. Wikipedia demurs. It says Hungerford was born on April 27.
Today is also National Petroleum Day. But is this a day to celebrate the miracles wrought by the internal combustion engine or to contemplate how we may break free of the chains of gasoline? Online sources differ; you are apparently free to decide for yourself.
Is an oil refinery a beautiful thing? How about a oil shale mine? Beauty is in the eye of the beholder, I suppose, but a future free of gasoline sounds more beautiful to me.