DateTimeCategoricalAxis FormatException

[LOUGE]

I'm trying to use LabelFormat in DateTimeCategoricalAxis but an exception occurs when i use H format string. =>it's work with HH for example
I want to use h (just hour with one digit for 1,2,3...), ddd, d (just day for 1,2,3...) and MMM in final testing

Xaml View :

<telerik:RadCartesianChart>

           <telerik:RadCartesianChart.HorizontalAxis>
               <telerik:DateTimeCategoricalAxis LabelFitMode="None"
                                                LabelFormat="H"
                                                DateTimeComponent="Hour" />
           </telerik:RadCartesianChart.HorizontalAxis>

           <telerik:RadCartesianChart.VerticalAxis>
               <telerik:LinearAxis />
           </telerik:RadCartesianChart.VerticalAxis>

           <telerik:LineSeries ItemsSource="{Binding}"
                               CategoryBinding="XValue"
                               ValueBinding="YValue"/>

       </telerik:RadCartesianChart>

Data object :

public class ChartData
   {
       public DateTime XValue
       {
           get;
           set;
       }

       public Double YValue
       {
           get;
           set;
       }
   }

Code for initialize data :

List<ChartData> datas = new List<ChartData>();

           for (int i = 0; i < 23; i++)
           {
               datas.Add(new ChartData
                   {
                       XValue = DateTime.Today.AddHours(i),
                       YValue = i
                   });
           }

           DataContext = datas;

[LOUGE]

%h do the trick, sorry