panel.add(picker);
VerticalPanel styling = new VerticalPanel();
panel.add(styling);
// 5th of each month is red.
RenderingHandler redHandler = new RenderingHandler() {
public void onRendered(RenderingEvent event) {
Date shown = picker.getDateShown();
Date d = new Date();
d.setYear(shown.getYear());
d.setMonth(shown.getMonth());