code: def zero_year_special_case(from_date, to_date, start, end):
      if start == 'pos' and end == 'pos':
          if from_date.startswith('0000') and not to_date.startswith('0000'):
              return True
          if not from_date.startswith('0000') and to_date.startswith('0000'):
              return False
          if from_date.startswith('0000') and to_date.startswith('0000'):
              if len(from_date) == 4:
                  fm, fd = 1, 1
              elif len(from_date) == 7:
                  fm, fd = int(from_date[5:7]), 1
              elif len(from_date) == 10:
                  fm, fd = int(from_date[5:7]), int(from_date[8:10])
              if len(to_date) == 4:
                  tm, td = 1, 1
              elif len(to_date) == 7:
                  tm, td = int(to_date[5:7]), 1
              elif len(to_date) == 10:
                  tm, td = int(to_date[5:7]), int(to_date[8:10])
              if from_date == to_date:
                  return True
              if fm <= tm:
                  if fd <= td:
                      return True
                  else:
                      return False
              else:
                  return False
      elif start == 'neg' and end == 'neg':
          return False
      elif start == 'neg' and end == 'pos':
          if from_date.startswith("0000"):
              return False
          else:
              return True