This can already perfectly be done in Messenger Plus!. Just use the task schedular, fill in the date, set it to "every year", et voila, your done....
And if you don't want to make it manually then ask someone to program a small app for you that sets the registry values itself
Do you want something outside Plus!? Then take a look at
Rainlendar, a very popular, totaly skinable, free and small program that puts a calendar on your desktop and has also a schedular with standard popups.