code: private int diff360EIsda(final LocalDate start, final LocalDate end) {
          if (start.equals(end)) {
              return 0;
          }
          int dayStart = start.getDayOfMonth();
          int dayEnd = end.getDayOfMonth();
          if (start.getMonth().length(start.isLeapYear()) == dayStart) {
              dayStart = CalculatorConstants.MONTH_30_DAYS;
          }
          if (end.getMonth() != Month.FEBRUARY && end.getMonth().length(end.isLeapYear()) == dayEnd) {
              dayEnd = CalculatorConstants.MONTH_30_DAYS;
          }
          return (end.getYear() - start.getYear()) * CalculatorConstants.YEAR_360 + (end.getMonthValue() - start.getMonthValue()) * CalculatorConstants.MONTH_30_DAYS + dayEnd - dayStart;
      }
docs: See https://en.wikipedia.org/wiki/Day_count_convention#30E.2F360_ISDA