MM are hand punched into the working die. There is only one way that you can have the same doubling on the MM and the date.
OK, our fellow enthusiasts gave you some answers (the right ones by the way). But why wasn't it DDD or a DDO?
I go for DDD (Die Deterioration Doubling) since the doubling shows up all around the character...the edges of the die are chipping or crumbling