code: private void readHolidays()
     {
        for (MapRow row : m_tables.get("HOL"))
        {
           ProjectCalendar calendar = m_calendarMap.get(row.getInteger("CALENDAR_ID"));
           if (calendar != null)
           {
              Date date = row.getDate("DATE");
              ProjectCalendarException exception = calendar.addCalendarException(date, date);
              if (row.getBoolean("ANNUAL"))
              {
                 RecurringData recurring = new RecurringData();
                 recurring.setRecurrenceType(RecurrenceType.YEARLY);
                 recurring.setYearlyAbsoluteFromDate(date);
                 recurring.setStartDate(date);
                 exception.setRecurring(recurring);
                 // TODO set end date based on project end date
              }
           }
        }
     }
docs: Read holidays from the database and create calendar exceptions.