Dictionaraddendum:

Because I simply cannot ignore the etymology behind the word "anniversary" and my grammar-senses tingle whenever I hear about someone's X-month anniverary...oh, wait, it looks like about three BILLION people (well, okay, 305 according to Google) have come up with the word mensiversary.

'kay, now instead of creating a new word, I am simply promoting its use. Ifeelkindasmallnow.