tree = (CommonTree)s.downup(tree);
// and walk it
nodes = new CommonTreeNodeStream(tree);
nodes.setTokenStream(stream);
DateWalker walker = new DateWalker(nodes);
walker.getState().setDefaultTimeZone(_defaultTimeZone);
walker.parse();
// run through the results and append the parse information
group = walker.getState().getDateGroup();
ParseLocation location = listener.getDateGroupLocation();
group.setLine(location.getLine());
group.setText(location.getText());
group.setPosition(location.getStart());
group.setSyntaxTree(tree);