code: def update_date_value_in_operator_value_pairs_for_fieldname(field, operator_value_pairs):
      
      updated_operator_value_pairs = {}
      for operator, value in operator_value_pairs.items():
          modified_date = _truncate_date_value_according_on_date_field(field, value)
          if not modified_date:
              return {}
  
          if operator == ES_RANGE_EQ_OPERATOR:
              updated_operator_value_pairs['gte'] = \
                  modified_date.dumps() + _get_proper_elastic_search_date_rounding_format(modified_date)
  
              next_date = _get_next_date_from_partial_date(modified_date)
              updated_operator_value_pairs['lt'] = \
                  next_date.dumps() + _get_proper_elastic_search_date_rounding_format(next_date)
          else:
              updated_operator_value_pairs[operator] = \
                  modified_date.dumps() + _get_proper_elastic_search_date_rounding_format(modified_date)
  
      return updated_operator_value_pairs
docs: Updates (operator, date value) pairs by normalizing the date value according to the given field.
  
      Args:
          field (unicode): The fieldname for which the operator-value pairs are being generated.
          operator_value_pairs (dict): ES range operator {'gt', 'gte', 'lt', 'lte'} along with a value.
              Additionally, if the operator is ``ES_RANGE_EQ_OPERATOR``, then it is indicated that the method should
              generate both a lower and an upper bound operator-value pairs, with the given date_value.
  
      Notes:
          On a ``ValueError`` an empty operator_value_pairs is returned.