The fact that D and I weren't married was never a problem - we still had our "anniversary". In fact, it was the anniversary of our first "date" (even though we almost never went on actual dates...). And it just so happened that it was April Fool's Day. That was always something I liked; it was a fun date to have as our anniversary, and it made gift-buying more amusing: we never bought each other "big" gifts, just small tokens, often with a joke theme, or (given that here in France April Fool's Day is "poisson d'avril" or April Fish) a fish theme.
Today would have been our 16th anniversary, although in fact we only made it past our 14th by a month (and trouble was well and truly looming for a while beforehand).
Now, April Fool's Day is a day tinged with sadness for me. The girls enjoy the French tradition of preparing paper fish and sticking them on the backs of friends and family without them knowing, but I can't quite get into the joyous mood. Especially this year, with the world crumbling around me.