Today as I was working on a manuscript, I came across the mention of New Years Eve and Valentines Day.  Out of curiosity, I Googled both terms to see what was most common in regards to using an apostrophe or not.

From a brief scan down the initial Google entries on New Years Eve, it appeared that there was no apostrophe.  Yet when I Googled Valentines Day, half the entries had an apostrophe and half didn’t.  Why the discrepency?  If the Eve belongs to the New Year, wouldn’t it be possessive?  And if the Day belongs to Valentine, wouldn’t that always be possessive too?

Apparently, both the Chicago Style Manual and the Gregg Reference Manual say they should have apostrophes after the “s”. 

However, holiday names are not all the same.  If you have a singular name, like the single New Year or Lincoln’s Birthday, the apostrophe goes before the “s”.  If you have a plural name, like April Fools’ Day or Presidents’ Day, the apostrophe comes after the “s”.  Then there are the holidays that don’t have an apostrophe in them at all, such as Veterans Day or Administrative Professionals Day.  Whoever made up the rules about whether to apostrophe or not in the holidays made them more of a headache than a celebration for writers!

It's Valentine's Day with an apostrophe!