public HBox buildDayRepeatButtons() {
        dayRepeatButtons = new HBox();
        Locale loc = Locale.getDefault();

        for(final DayOfWeek day : DayOfWeek.values()) {
            String label = day.getDisplayName(TextStyle.SHORT, loc);
            final ToggleButton dayButton = new ToggleButton(label);

            dayButton.setOnAction(new EventHandler<ActionEvent>() {
                @Override
                public void handle(ActionEvent event) {
                    changeRepeatDays(day);
                }
            });

            dayRepeatButtons.getChildren().add(dayButton);
        }
        dayRepeatButtons.setDisable(true);
        return dayRepeatButtons;
    }