Happy Birthday Charm Vintage Calendar Mechanical Date BeadRage

A unique mechanical Birthday charm or zipper pull. It's a bigger charm measuring 1 1/8" across - there are 2 tabs that change the month and date to fit your birthday. Says Happy Birthday in script across the front. There are absolutely no marks indicating whomade this piece. It has a regular jump ring attachment. It does not test positive for sterling. I put this piece in sterling charm catagory but it is NOT sterling. Just didn't know where to put it.