code: def is_businessdate(in_date):
          
          # Note: if the data range has been created from pace_xl, then all the dates are bank dates
          # and here it remains to check the validity.
          # !!! However, if the data has been read from json string via json.load() function
          # it does not recognize that this numbers are bankdates, just considers them as integers
          # therefore, additional check is useful here, first to convert the date if it is integer to BusinessDate,
          # then check the validity.
          # (as the parameter to this method should always be a BusinessDate)
          if not isinstance(in_date, BaseDate):
              try:  # to be removed
                  in_date = BusinessDate(in_date)
              except:
                  return False
          y, m, d, = in_date.to_ymd()
          return is_valid_ymd(y, m, d)
docs: checks whether the provided date is a date
          :param BusinessDate, int or float in_date:
          :return bool: