code: public static int getWeekDays (@Nonnull final LocalDate aStartDate, @Nonnull final LocalDate aEndDate)
    {
      ValueEnforcer.notNull (aStartDate, "StartDate");
      ValueEnforcer.notNull (aEndDate, "EndDate");
  
      final boolean bFlip = aStartDate.isAfter (aEndDate);
      LocalDate aCurDate = bFlip ? aEndDate : aStartDate;
      final LocalDate aRealEndDate = bFlip ? aStartDate : aEndDate;
  
      int ret = 0;
      while (!aRealEndDate.isBefore (aCurDate))
      {
        if (!isWeekend (aCurDate))
          ret++;
        aCurDate = aCurDate.plusDays (1);
      }
      return bFlip ? -1 * ret : ret;
    }
docs: Count all non-weekend days in the range. Does not consider holidays!
  
  @param aStartDate
  start date
  @param aEndDate
  end date
  @return days not counting Saturdays and Sundays. If start date is after end
  date, the value will be negative! If start date equals end date the
  return will be 1 if it is a week day.