chbConference.setOnAction(event -> {
                maxDays = 0;
                Conference con = chbConference.getSelectionModel().getSelectedItem();
                if (con != null) {
                    maxDays = (int) ChronoUnit.DAYS.between(con.getStartDate(), con.getEndDate());
                }
                lblDays.setText("Days: " + "(max " + maxDays + " days)");
        });