It seems to me I keep seeing people who talk about their “one-month anniversary” or some other less-than-a-year interval. I think I need to point out that this is WRONG! (I need to find that sound clip of infamous Senator Robert Byrd that Sean Hannity uses.)
If you actuallly look at the definition of the word anniversary, it says: “The annually recurring date of a past event, especially one of historical, national, or personal importance.” You probably don’t even need that definition, as most people would know the word derives from the Latin root annus, which means year. It is correct to say “I’ve been dating so-and-so for a month,” but totally incorrect to say, “The two of us celebrated our four-week anniversary.” It is also terribly redundunt to say that you’re celebrating a “[cardinal number]-year anniversary.” Just say “[ordinal number] anniversary,” and you’ll be correct.
We now return you to your Saturday-morning cartoon watching. ;p