code: private void addWeekdayLabels() {
          weekdayLabels = new ArrayList<JLabel>();
          int weekdayLabelRowY = constantFirstWeekdayLabelCell.y;
          int weekdayLabelWidthInCells = 1;
          int weekdayLabelHeightInCells = 3;
          for (int i = 0; i < 7; ++i) {
              int weekdayLabelColumnX = (i + constantFirstWeekdayLabelCell.x);
              JLabel weekdayLabel = new JLabel();
              weekdayLabel.setHorizontalAlignment(SwingConstants.CENTER);
              weekdayLabel.setVerticalAlignment(SwingConstants.CENTER);
              weekdayLabel.setBorder(new EmptyBorder(0, 2, 0, 2));
              weekdayLabel.setOpaque(true);
              weekdayLabel.setText("wd" + i);
              CellConstraints constraints = CC.xywh(weekdayLabelColumnX, weekdayLabelRowY,
                  weekdayLabelWidthInCells, weekdayLabelHeightInCells);
              centerPanel.add(weekdayLabel, constraints);
              weekdayLabels.add(weekdayLabel);
          }
      }
docs: addWeekdayLabels, This adds a set of 7 weekday labels to the calendar panel. The text of
  these labels is set with locale sensitive weekday names each time that the calendar is
  redrawn.
  
  This function should not depend on any settings variables.