Event reminder mod

[DaveS]

I'm after a mod that will allow a user to add a private event (that no-one else should see) and get an email just before that event is due.
So perhaps you want to remember your friends birthday or an anniversary.... that sort of thing.

I've searched everywhere and can't find anything and I don't really think that the calendart functionality is flexible enough to do this.

Any ideas?
TIA Dave.