timeline.setBrowserOutlineColor(graphDataSource, Color.BLACK);
timeline.setBrowserFillColor(graphDataSource, new Color(0,0,0,128));
//adding a listener
timeline.addListener(new Timeline.EventClickListener(){
@Override
public void eventClick(EventButtonClickEvent event) {
Item item = eventDataSource.getItem(event.getItemIds().iterator().next());
Date sunday = (Date) item.getItemProperty(Timeline.PropertyId.TIMESTAMP).getValue();