We know for sure that it’s the third Monday in February. But how do you spell the name of that holiday?
The two sources I use most frequently, the Associated Press Stylebook and Merriam-Webster’s Collegiate Dictionary, differ. The AP says Presidents Day, with no apostrophe. M-W has it as Presidents’ Day. The New York Times devoted an article to the debate, broadening the discussion to include other disputed apostrophes, but reached no definitive conclusion.
So what’s right: President’s, Presidents’ or Presidents Day? All of them, and any of them. Just pick one, and stick to it. Being consistent is more important than being right all the time.
And if you don’t have the time to check every word yourself, hire a smart editor to do it for you.