docs: def min_date(self, symbol):
          """
          Return the minimum datetime stored for a particular symbol
  
          Parameters
          ----------
          symbol : `str`
              symbol name for the item
          """
          res = self._collection.find_one({SYMBOL: symbol}, projection={ID: 0, START: 1},
                                          sort=[(START, pymongo.ASCENDING)])
          if res is None:
              raise NoDataFoundException("No Data found for {}".format(symbol))
          return utc_dt_to_local_dt(res[START])