code: def create(self, price_estimate):
          
          kwargs = {}
          try:
              previous_price_estimate = price_estimate.get_previous()
          except ObjectDoesNotExist:
              pass
          else:
              configuration = previous_price_estimate.consumption_details.configuration
              kwargs['configuration'] = configuration
          month_start = core_utils.month_start(datetime.date(price_estimate.year, price_estimate.month, 1))
          kwargs['last_update_time'] = month_start
          return super(ConsumptionDetailsQuerySet, self).create(price_estimate=price_estimate, **kwargs)
docs: Take configuration from previous month, it it exists.
              Set last_update_time equals to the beginning of the month.