telerikInput:RadTimePicker bind its selection to view model

        <telerikInput:RadTimePicker Time="{Binding SelectedTime, Mode=TwoWay}"/>

public class ViewModel : INotifyPropertyChanged
{
    private TimeSpan? selectedTime;
    public ViewModel()
    {
        this.SelectedTime = new TimeSpan(1, 2, 3, 4);
    }
    public TimeSpan? SelectedTime
    {
        get { return this.selectedTime; }
        set
        {
            if (this.selectedTime != value)
                this.selectedTime = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("SelectedTime"));

        }
    }
}