Some bright spark has decided that since our school is a language college we ought to be making multi-lingual "Merry Christmas posters (not me I hasten to add!). Anyway, the scientist in question got the ball rolling by putting Merry Christmas into some kind of translation contraption and asking the linguists to correct the resulting mess.
In the midst of said mess was something purporting to be the Latin for Merry Christmas, and as the proud possessor of a GCSE in said language it was assumed that I could sort it out. Now, if it were one of those nice, safe passive translations - or better yet the prepared passages from Caesar's Gallic War I'd chance my arm...but let's be honest there are some real Latinists here and I'm sure you'd do a better job of it than I. I've seen felix dies navitatis touted as a possiblity on t'interweb. Suggestions please
I think your best bet for Merry Christmas would be dies nativitatis hilaris, or perhaps dies nativitatis festiva. I prefer the first of these. Some purists would frown at Church Latin nativitatis. If so, substitute Christi natalis. Dies Christi natalis hilaris has quite a good rhythm to it.
Risking an OFLIT condemnation for loose dynamic equivalence - why not just go for the good old....... Gaudete! Gaudete! Christus est natus ex Maria Virgine, Gaudete! ...... it's a good tune!
Thank you gentlemen. Thanks also to Presbyter for his suggestion - but the only Latin we'll be singing at school this Christmas is the version of Reno erat Rodolphus that appeared here last year, perhaps the year before - it's acquired the force of immemorial custom with my form!