chart 3.2.0 date format "{value:%Y-%m-%d}" dont work

I need to format the date ,but It didnt work in the below two ways,please help me ,thanks 
1. The chart line wont be formatted by this way.
        PlotOptionsLine limitationOpts = new PlotOptionsLine();
        limitationOpts.getDataLabels().setFormat("{value:%Y-%m-%d}");
 2. Navigator also didnt work in this way.
     com.vaadin.addon.charts.model.Navigator navigator = conf.getNavigator();
    navigator.getSeries().getDataLabels().setFormat("{value:%Y-%m-%d}");     

Hi. I don't know why that format doesn't work. Try {x:%Y-%m-%d}