I am using a datepicker in C# WPF and it is defined in XAML as:

```
  <DatePicker  x:Name="TheDate"  Width="200" Text="{Binding ReportPlanningDate ,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=True}" IsTodayHighlighted="True" />

```

Binding property `ReportPlanningDate` is defined as:

```
public DateTime ReportPlanningDate
        {
            get { return _ReportPlanningDate; }
            set
            {
                if (_ReportPlanningDate == value) return;
                _ReportPlanningDate = value;
                PlanningDate = _ReportPlanningDate;
                OnPropertyChanged("ReportPlanningDate");
            }
        }
        public DateTime _ReportPlanningDate;
        public DateTime PlanningDate;

```

Even though I set `IsTodayHighlighted` to `True`, it displays `1/1/0001`. What am I missing here?