docs: def _get_daily_date_range(self, metric_date, delta):
          """
          Get the range of months that we need to use as keys to scan redis.
          """
          dates = [metric_date]
          start_date = metric_date
          end_date = metric_date + delta
  
          while start_date.month < end_date.month or start_date.year < end_date.year:
              days_in_month = calendar.monthrange(start_date.year, start_date.month)[1]
              #shift along to the next month as one of the months we will have to see. We don't care that the exact date
              #is the 1st in each subsequent date range as we only care about the year and the month
              start_date = start_date + datetime.timedelta(days=days_in_month - start_date.day + 1)
              dates.append(start_date)
  
          return dates