code: def get_birthday(code):
      
      assert isvalid(code)
  
      day = int(code[9:11])
      day = day < 32 and day or day - 40
  
      month = MONTHSCODE.index(code[8]) + 1
      year = int(code[6:8])
  
      return "%02d-%02d-%02d" % (day, month, year)
docs: ``get_birthday(code) -> string``
  
      Birthday of the person whose fiscal code is 'code', in the format DD-MM-YY. 
  
      Unfortunately it's not possible to guess the four digit birth year, given
      that the Italian fiscal code uses only the last two digits (1983 -> 83).
      Therefore, this function returns a string and not a datetime object.
  
      eg: birthday('RCCMNL83S18D969H') -> 18-11-83