Anniversaries come once a year

I've had it up to here with anniversaries. No, I'm not saying I won't buy my beloved some token gift when the time comes round again, I mean I am fed up with the current fad for the tautology of the "n year anniversary". "Anniversary" comes from the Latin "anniversarius" meaning returning yearly. That in turn is made up of "annus" (year), "versus" (turned, or a turning) and the suffix "-arius" (connected with, pertaining to). There is no need to say "year" when using "anniversary".

Now we might sometimes use anniversary playfully in something like "six month anniversary", which is also wrong but I can accept it as an informal expression and there isn't really a good formal alternative. "Mensiversary" could work, derived from the Latin "mensis" (month) but it won't be widely understood.