xaml code

<DatePicker x:Name="PatientDateOfBirthPicker"
                        SelectedDateChanged="PatientDateOfBirthPicker_SelectedDateChanged"
                        Header="بەرواری لە دایک بوون"
                        DayFormat="day"
                        MonthFormat="{}{month.integer}"
                        YearFormat="{}{year.full(4)}"
                        YearVisible="True"
                        FontFamily="NRT Reg"
                        FontSize="18" 
                        FlowDirection="RightToLeft"
                        Width="400">
            </DatePicker>

How to change header text align to right tried both FlowDirection="RightToLeft" and FlowDirection="LeftToRight" it give me the same result