Good Grammar in Massachusetts.

Today is Patriots' Day, a holiday in the U.S. state of Massachusetts. (in honor of the anniversary of the Battle of Lexington and Concord on April 19, 1775, which has is seen as the beginning of the American Revolution) - even though Harvard is not on holiday.
Interestingly, you can find three different spellings of the day in question

• Patriots Day
  

• Patriots’ Day

• Patriot’s Day.

Which one do you think is actually the most correct one?

Language Log and Wikipedia are both right: the three forms are grammatically correct. Having recently read a lot of linguistics lately, I can add that even though there are all fully grammatical, they imply a slightly different view point.

I will not go into technical details but if there is one thing I enjoy about modern linguistics (as opposed to prescriptive grammar, i.e. the way my generation learned English) – it is that it does not give you rules to apply, it only deals with the form of a language at a given moment, the changes of that language, and the context in which it is used. It is therefore a very empirical discipline in touch with reality which does not or should not concern itself with correctness. In other words, linguistics is by essence the epitome of liberal arts.

By the way, this question about Massachusetts’s holiday is only one found in writing as phonetically the three phrases are exactly the same.