It’s Christmas Eve. (Merry Christmas Eve!)
Yesterday I had to clarify what exactly “New Year’s Eve” was, and my friend (let’s just call him A) had no whether I was messing with him or not. I wasn’t. I was genuinely confused.
I mean, I know that the colloquial term of Something Eve means the day before Something, hence Christmas Eve is the day before Christmas, but literarily (literarily not literally), eve just means evening. I even referred to the dictionary for this. Basically, Christmas Eve should mean the eve of Christmas, not the eve before Christmas. If you were to mean the eve of Christmas, why not just say “eve of Christmas”??
Anyway, the point is, English is really weird.