code: public String describeMonth(final Map<CronFieldName, CronField> fields) {
          final String description = DescriptionStrategyFactory.monthsInstance(
                  resourceBundle,
                  fields.containsKey(CronFieldName.MONTH) ? fields.get(CronFieldName.MONTH).getExpression() : null
          ).describe();
  
          return addTimeExpressions(description, resourceBundle.getString("month"), resourceBundle.getString("months"));
      }
docs: Provide description for month.
  
  @param fields - fields to describe;
  @return description - String