Criticism (as an-end user):

  1. Show birthday as well as current date on userform.
  2. Make 'Set Birthday' form larger as to see the day numbers
  3. Make 'Set Birthday' button a little more prominent


Well that's what I'd do. I realize this was done per an OP's spec's, just me being critical (I'm really no judge, but I'd like someone to do the same for me). It is really cool though!! Nice job!!