Whatever you're doing today, wherever you might be, take a moment to reflect on the most popular word in the English language, OK?
It will be 175 years since OK - or, as some prefer, okay - first appeared in print, on page two of The Boston Morning Post, then one of the most popular newspapers in the United States.
"I think OK should be celebrated with parades and speeches," Allan Metcalf, an English professor in Illinois who is the world's leading authority on the history and meaning of OK, said.
"But for now, whatever you do [to mark the anniversary], it's OK."
In his 2001 book, OK: The Improbable Story of America's Greatest Word, Metcalf calls OK "the most frequently spoken (or typed) word on the planet".
Concise and utilitarian, it's quintessentially American in its simplicity. Etymologically, it has no direct relationship with Latin or Greek or any other ancient tongue.
Oxford Dictionaries, on its website, rejects speculation that OK is derived from the Scottish expression "och aye," the Greek "ola kala" (it's good) or the French "aux Cayes," which refers to a Haitian port famous for its rum.
Rather, it favours a theory - shared by Metcalf - that it's an abbreviation of "orl korrekt," a derivative of "all correct" from the 1830s when jokey misspellings were all the rage.
Credit for finding its first use in print goes to Allen Walker Read, a Columbia University professor who died in 2002 after a lifetime interest in OK and another widely used word with four letters that starts with the letter F.
It appeared in the Post in the context of an article concerning the ironically named Anti-Bell Ringing Society, founded in 1838 to oppose a municipal law in Boston prohibiting the ringing of dinner bells.
Society members were on their way to New York, it reported, adding cryptically that if they should travel through Rhode Island en route home, the newspaper editor in the New England state might well "have the 'contribution box,' et ceteras, o.k. - all correct - and cause the corks to fly, like sparks, upward."
Other abbreviations proliferated at the time, like NG for "no go," GT for "gone to Texas" and SP for "small potatoes."
But OK truly entered America's lingua franca in 1840, when spin doctors for Democratic presidential nominee Martin Van Buren, a native of Kinderhook, New York, insisted to voters that it meant "Old Kinderhook."
Internationally, OK has travelled remarkably well - including in Hong Kong, where "OK la" has become common parlance.