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WPF DatePicker Icon Size

I have a DatePicker like this:
<DatePicker Grid.Row="7" HorizontalAlignment="Left" FontSize="43" CalendarStyle="{StaticResource styleCalendar}"/>
The problem is, that increasing the font size of the date picker doesn't resize the icon and it remains small.
I've searched but couldn't find a proper way to only resize the icon, or maybe this is not the proper way of enlarging the whold picker

For people who are not satisfied with the simple answers from Michael Repucci there is a "cleaner" alternative solution to my taste which allows you to surround only the icon by a viewbox.
You can right click on the element you want to modify on the Design panel of an xaml file and click on "modify model". This will take you to the xaml code of the element. Then you have to locate the part you want to modify. Here I have surrounded only the Button that contains the icon with a ViewBox and not the whole control.
The part in question is almost at the bottom. I put some line feeds to make it more visible.
<Style x:Key="DatePickerIconResizingStyle" TargetType="{x:Type DatePicker}">
<Setter Property="Foreground" Value="#FF333333"/>
<Setter Property="IsTodayHighlighted" Value="True"/>
<Setter Property="SelectedDateFormat" Value="Short"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Padding" Value="2"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DatePicker}">
<Border Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Padding="{TemplateBinding Padding}">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Duration="0" Storyboard.TargetName="PART_DisabledVisual" Storyboard.TargetProperty="Opacity" To="1"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid x:Name="PART_Root" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<Grid.Resources>
<SolidColorBrush x:Key="DisabledBrush" Color="#A5FFFFFF"/>
<ControlTemplate x:Key="DropDownButtonTemplate" TargetType="{x:Type Button}">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="Pressed"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" Storyboard.TargetName="Background" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" To="#FF448DCA"/>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#7FFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#CCFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#F2FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="Background" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#FF448DCA"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="Highlight" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#EAFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#C6FFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#6BFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetName="BackgroundGradient" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)">
<SplineColorKeyFrame KeyTime="0" Value="#F4FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid Background="#11FFFFFF" FlowDirection="LeftToRight" HorizontalAlignment="Center" Height="18" Margin="0" VerticalAlignment="Center" Width="19">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="23*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
</Grid.RowDefinitions>
<Border x:Name="Highlight" BorderThickness="1" BorderBrush="#FF45D6FA" CornerRadius="0,0,1,1" Grid.ColumnSpan="4" Margin="-1" Opacity="0" Grid.RowSpan="4" Grid.Row="0"/>
<Border x:Name="Background" Background="#FF1F3B53" BorderThickness="1" BorderBrush="#FFFFFFFF" CornerRadius=".5" Grid.ColumnSpan="4" Margin="0,-1,0,0" Opacity="1" Grid.RowSpan="3" Grid.Row="1"/>
<Border x:Name="BackgroundGradient" BorderThickness="1" BorderBrush="#BF000000" CornerRadius=".5" Grid.ColumnSpan="4" Margin="0,-1,0,0" Opacity="1" Grid.RowSpan="3" Grid.Row="1">
<Border.Background>
<LinearGradientBrush EndPoint=".7,1" StartPoint=".7,0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#F9FFFFFF" Offset="0.375"/>
<GradientStop Color="#E5FFFFFF" Offset="0.625"/>
<GradientStop Color="#C6FFFFFF" Offset="1"/>
</LinearGradientBrush>
</Border.Background>
</Border>
<Rectangle Grid.ColumnSpan="4" Grid.RowSpan="1" StrokeThickness="1">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.3,-1.1" StartPoint="0.46,1.6">
<GradientStop Color="#FF4084BD"/>
<GradientStop Color="#FFAFCFEA" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
<Rectangle.Stroke>
<LinearGradientBrush EndPoint="0.48,-1" StartPoint="0.48,1.25">
<GradientStop Color="#FF494949"/>
<GradientStop Color="#FF9F9F9F" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Stroke>
</Rectangle>
<Path Grid.ColumnSpan="4" Grid.Column="0" Data="M11.426758,8.4305077 L11.749023,8.4305077 L11.749023,16.331387 L10.674805,16.331387 L10.674805,10.299648 L9.0742188,11.298672 L9.0742188,10.294277 C9.4788408,10.090176 9.9094238,9.8090878 10.365967,9.4510155 C10.82251,9.0929432 11.176106,8.7527733 11.426758,8.4305077 z M14.65086,8.4305077 L18.566387,8.4305077 L18.566387,9.3435936 L15.671368,9.3435936 L15.671368,11.255703 C15.936341,11.058764 16.27293,10.960293 16.681133,10.960293 C17.411602,10.960293 17.969301,11.178717 18.354229,11.615566 C18.739157,12.052416 18.931622,12.673672 18.931622,13.479336 C18.931622,15.452317 18.052553,16.438808 16.294415,16.438808 C15.560365,16.438808 14.951641,16.234707 14.468243,15.826504 L14.881817,14.929531 C15.368796,15.326992 15.837872,15.525723 16.289043,15.525723 C17.298809,15.525723 17.803692,14.895514 17.803692,13.635098 C17.803692,12.460618 17.305971,11.873379 16.310528,11.873379 C15.83071,11.873379 15.399232,12.079271 15.016094,12.491055 L14.65086,12.238613 z" Fill="#FF2F2F2F" HorizontalAlignment="Center" Margin="4,3,4,3" RenderTransformOrigin="0.5,0.5" Grid.RowSpan="3" Grid.Row="1" Stretch="Fill" VerticalAlignment="Center"/>
<Ellipse Grid.ColumnSpan="4" Fill="#FFFFFFFF" HorizontalAlignment="Center" Height="3" StrokeThickness="0" VerticalAlignment="Center" Width="3"/>
<Border x:Name="DisabledVisual" BorderThickness="1" BorderBrush="#B2FFFFFF" CornerRadius="0,0,.5,.5" Grid.ColumnSpan="4" Opacity="0" Grid.RowSpan="4" Grid.Row="0"/>
</Grid>
</Grid>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<!-- This ViewBox allows to resize the icon automatically to fill the full height of the DatePicker -->
<Viewbox Grid.Column="1" HorizontalAlignment="Left" Margin="3,0,3,0" Grid.Row="0" VerticalAlignment="Top">
<Button x:Name="PART_Button" Focusable="False" Foreground="{TemplateBinding Foreground}" Template="{StaticResource DropDownButtonTemplate}" />
</Viewbox>
<DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" Focusable="{TemplateBinding Focusable}" HorizontalContentAlignment="Stretch" Grid.Row="0" VerticalContentAlignment="Stretch"/>
<Grid x:Name="PART_DisabledVisual" Grid.ColumnSpan="2" Grid.Column="0" IsHitTestVisible="False" Opacity="0" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0" Fill="#A5FFFFFF" RadiusX="1" RadiusY="1" Grid.Row="0"/>
<Rectangle Grid.Column="1" Fill="#A5FFFFFF" Height="18" Margin="3,0,3,0" RadiusX="1" RadiusY="1" Grid.Row="0" Width="19"/>
<Popup x:Name="PART_Popup" AllowsTransparency="True" Placement="Bottom" PlacementTarget="{Binding ElementName=PART_TextBox}" StaysOpen="False"/>
</Grid>
</Grid>
</Border>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Source={x:Static SystemParameters.HighContrast}}" Value="false">
<Setter Property="Foreground" TargetName="PART_TextBox" Value="{Binding Foreground, RelativeSource={RelativeSource TemplatedParent}}"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
I hope this answer will help someone.

The easiest way to do this is to put the DatePicker into a Viewbox and adjust the size of the Viewbox. So borrowing from your example, you might have
<Viewbox Grid.Row="7" HorizontalAlignment="Left" Width="150">
<DatePicker CalendarStyle="{StaticResource styleCalendar}"/>
</Viewbox>
where increasing/decreasing the Viewbox.Width parameter will allow you to adjust the size of the DatePicker.

For me the solution that worked was to put only the calendar button inside a viewbox.
<DatePicker...>
<DatePicker.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Viewbox>
<ContentPresenter/>
</Viewbox>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePicker.Resources>
</DatePicker>

WPF DatePicker format

I got this sample code from this forum.
<DatePicker SelectedDate="{Binding myVideModelProperty}"
Height="25" HorizontalAlignment="Left" Margin="81,-2,0,0" Name="myDatePicker" VerticalAlignment="Top" Width="115">
<DatePicker.Resources>
<Style TargetType="{x:Type DatePickerTextBox}">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<TextBox x:Name="PART_TextBox"
Text="{Binding Path=SelectedDate, RelativeSource={RelativeSource AncestorType={x:Type DatePicker}}, StringFormat={}{0:yyyy/MM/dd}}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePicker.Resources>
</DatePicker>
But I want the format i.e yyyy/MM/dd to come from an application property called dateformat.
Can you help me put the stringformat as a binding to the application property.

All of the other answers seem a little bit convoluted. It is as simple as:
<DatePicker SelectedDate="{Binding PropertyName, StringFormat=dd/MM/yyyy}"/>
All you need to do is adjust the string format to suit yourself.

Use this snippet for your DatePicker (you will have to style it):
<DatePicker SelectedDate="{Binding myVideModelProperty}">
<DatePicker.Resources>
<Style TargetType="{x:Type DatePickerTextBox}">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<TextBox x:Name="PART_TextBox"
Text="{Binding Path=SelectedDate,
RelativeSource={RelativeSource AncestorType={x:Type DatePicker}},
StringFormat={x:Static local:App.DateFormat}}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePicker.Resources>
</DatePicker>
Use this snippet for your App.xaml.cs (change the namespace to something useful):
namespace _24417730
{
public partial class App
{
public static string DateFormat = "yyyy/MM/dd";
}
}
In the xaml control containing your DatePicker, define a XAML namespace like so:
xmlns:local="clr-namespace:_24417730"
Note that you will have to change the namespace to the one you used to define your application class.
Here is how I defined my xaml namespace on the MainWindow.xaml control:
<Window x:Class="_24417730.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:_24417730"
Title="MainWindow" Height="350" Width="525">
<StackPanel>
<DatePicker SelectedDate="{Binding myVideModelProperty}">
<DatePicker.Resources>
<Style TargetType="{x:Type DatePickerTextBox}">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<TextBox x:Name="PART_TextBox"
Text="{Binding Path=SelectedDate,
RelativeSource={RelativeSource AncestorType={x:Type DatePicker}},
StringFormat={x:Static local:App.DateFormat}}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePicker.Resources>
</DatePicker>
</StackPanel>
</Window>
Also, reading up on Static Markup Extension and XAML Namespaces may help for future reference.
If you require any further clarifications, I will be happy to assist.

You can use converters for that.
Or you can add another property to your class which will return the formatted date.
With converter
public class DateFormatConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return string.Format(Application.DateFormat, value);
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
}
}

<Style TargetType="{x:Type DatePicker}">
<Setter Property="Foreground" Value="#FF333333"/>
<Setter Property="IsTodayHighlighted" Value="True"/>
<Setter Property="SelectedDateFormat" Value="Short"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Padding" Value="2"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint=".5,0" StartPoint=".5,1">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DatePicker}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_DisabledVisual"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid x:Name="PART_Root" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<Grid.Resources>
<SolidColorBrush x:Key="DisabledBrush" Color="#A5FFFFFF"/>
<ControlTemplate x:Key="DropDownButtonTemplate" TargetType="{x:Type Button}">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="MouseOver"/>
<VisualTransition GeneratedDuration="0:0:0.1" To="Pressed"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Duration="0" To="#FF448DCA" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background"/>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#7FFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#CCFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F2FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(SolidColorBrush.Color)" Storyboard.TargetName="Background">
<SplineColorKeyFrame KeyTime="0" Value="#FF448DCA"/>
</ColorAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="Highlight">
<SplineDoubleKeyFrame KeyTime="0" Value="1"/>
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[1].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#EAFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[2].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#C6FFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[3].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#6BFFFFFF"/>
</ColorAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="0" Duration="00:00:00.001" Storyboard.TargetProperty="(Border.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)" Storyboard.TargetName="BackgroundGradient">
<SplineColorKeyFrame KeyTime="0" Value="#F4FFFFFF"/>
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid Background="#11FFFFFF" FlowDirection="LeftToRight" HorizontalAlignment="Center" Height="18" Margin="0" VerticalAlignment="Center" Width="19">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
<ColumnDefinition Width="20*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="23*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
<RowDefinition Height="19*"/>
</Grid.RowDefinitions>
<Border x:Name="Highlight" BorderBrush="#FF45D6FA" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,1,1" Margin="-1" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
<Border x:Name="Background" BorderBrush="#FFFFFFFF" BorderThickness="1" Background="#FF1F3B53" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3"/>
<Border x:Name="BackgroundGradient" BorderBrush="#BF000000" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius=".5" Margin="0,-1,0,0" Opacity="1" Grid.Row="1" Grid.RowSpan="3">
<Border.Background>
<LinearGradientBrush EndPoint=".7,1" StartPoint=".7,0">
<GradientStop Color="#FFFFFFFF" Offset="0"/>
<GradientStop Color="#F9FFFFFF" Offset="0.375"/>
<GradientStop Color="#E5FFFFFF" Offset="0.625"/>
<GradientStop Color="#C6FFFFFF" Offset="1"/>
</LinearGradientBrush>
</Border.Background>
</Border>
<Rectangle Grid.ColumnSpan="4" Grid.RowSpan="1" StrokeThickness="1">
<Rectangle.Fill>
<LinearGradientBrush EndPoint="0.3,-1.1" StartPoint="0.46,1.6">
<GradientStop Color="#FF4084BD"/>
<GradientStop Color="#FFAFCFEA" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Fill>
<Rectangle.Stroke>
<LinearGradientBrush EndPoint="0.48,-1" StartPoint="0.48,1.25">
<GradientStop Color="#FF494949"/>
<GradientStop Color="#FF9F9F9F" Offset="1"/>
</LinearGradientBrush>
</Rectangle.Stroke>
</Rectangle>
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<Border x:Name="DisabledVisual" BorderBrush="#B2FFFFFF" BorderThickness="1" Grid.ColumnSpan="4" CornerRadius="0,0,.5,.5" Opacity="0" Grid.Row="0" Grid.RowSpan="4"/>
</Grid>
</Grid>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Button x:Name="PART_Button" Grid.Column="1" Foreground="{TemplateBinding Foreground}" Focusable="False" HorizontalAlignment="Left" Margin="3,0,3,0" Grid.Row="0" Template="{StaticResource DropDownButtonTemplate}" VerticalAlignment="Top" Width="20"/>
<DatePickerTextBox x:Name="PART_TextBox" Grid.Column="0" Focusable="{TemplateBinding Focusable}" HorizontalContentAlignment="Stretch" Grid.Row="0" VerticalContentAlignment="Stretch" Text="{Binding SelectedDate,RelativeSource={RelativeSource TemplatedParent},StringFormat='dd/MM/yyyy'}" />
<Grid x:Name="PART_DisabledVisual" Grid.ColumnSpan="2" Grid.Column="0" IsHitTestVisible="False" Opacity="0" Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Rectangle Grid.Column="0" Fill="#A5FFFFFF" RadiusY="1" Grid.Row="0" RadiusX="1"/>
<Rectangle Grid.Column="1" Fill="#A5FFFFFF" Height="18" Margin="3,0,3,0" RadiusY="1" Grid.Row="0" RadiusX="1" Width="19"/>
<Popup x:Name="PART_Popup" AllowsTransparency="True" Placement="Bottom" PlacementTarget="{Binding ElementName=PART_TextBox}" StaysOpen="False"/>
</Grid>
</Grid>
</Border>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Source={x:Static SystemParameters.HighContrast}}" Value="false">
<Setter Property="Foreground" TargetName="PART_TextBox" Value="{Binding Foreground, RelativeSource={RelativeSource TemplatedParent}}"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Add a Style for DatePickerTextBox like this, no CultureInfo required, make the format you want with StringFormat:
<DatePicker SelectedDate="{Binding myProperty}">
<DatePicker.Resources>
<Style TargetType="{x:Type DatePickerTextBox}">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<TextBox x:Name="PART_TextBox" Text="{Binding Path=SelectedDate, StringFormat='dd MMMM yyyy', RelativeSource={RelativeSource AncestorType={x:Type DatePicker}}}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DatePicker.Resources>
</DatePicker>

Most of the time, when you want to change date format, it's usually because your had the wrong culture.
Set the current thread culture correctly :
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("fr-FR");
After that, if the culture format is still not ok for you, you can change it via ShortDatePattern and LongDatePattern properties of CulureInfo.
ci.DateTimeFormat.ShortDatePattern = "dd/MM/yyyy"; //where ci a CultureInfo object
Finally you can tell DatePicker to prefer Short or Long format via SelectedDateFormat property.

How to custom WPF Calendar?

I want to custom my own calendar style. I have searched on internet and I have got the following example:
<Style x:Key="PlaybackCalendarItemStyle" TargetType="primitives:CalendarItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="primitives:CalendarItem">
<ControlTemplate.Resources>
<!-- Start: Data template for header button -->
<DataTemplate x:Key="DayTitleTemplate">
<TextBlock
FontWeight="Bold"
FontFamily="Verdana"
FontSize="9.5"
Foreground="#FF333333"
HorizontalAlignment="Center"
Text="{Binding}"
Margin="0,6,0,6"
VerticalAlignment="Center"/>
</DataTemplate>
<!-- End: Data template for header button -->
</ControlTemplate.Resources>
<Grid Name="PART_Root" >
<Grid.Resources>
<SolidColorBrush x:Key="DisabledColor" Color="#A5FFFFFF" />
</Grid.Resources>
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="CommonStates">
<vsm:VisualState x:Name="Normal" />
<vsm:VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="PART_DisabledVisual" Storyboard.TargetProperty="Opacity" To="1" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Border
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
CornerRadius="1">
<!-- This Brush is new -->
<Border.Background>
<LinearGradientBrush StartPoint="0 0" EndPoint="0 1">
<GradientStop Offset="0" Color="#FFFFC0" />
<GradientStop Offset="0.5" Color="#FFE0B0" />
<GradientStop Offset="1" Color="#FFD0A8" />
</LinearGradientBrush>
</Border.Background>
<Border CornerRadius="1" BorderBrush="#FFFFFFFF" BorderThickness="2">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.Resources>
<!-- Start: Previous button template -->
<ControlTemplate x:Key="PreviousButtonTemplate" TargetType="Button">
<Grid Cursor="Hand">
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="CommonStates">
<vsm:VisualState x:Name="Normal" />
<vsm:VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Storyboard.TargetName="TextColor" Storyboard.TargetProperty="Color" To="#FF73A9D8" Duration="0" />
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="TextColor" Storyboard.TargetProperty="Opacity" To=".5" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Rectangle Fill="#11E5EBF1" Stretch="Fill" Opacity="1"/>
<Grid>
<Path Margin="14,-6,0,0" Height="10" Width="6" VerticalAlignment="Center" HorizontalAlignment="Left" Stretch="Fill" Data="M288.75,232.25 L288.75,240.625 L283,236.625 z">
<Path.Fill>
<SolidColorBrush x:Name="TextColor" Color="#FF333333" />
</Path.Fill>
</Path>
</Grid>
</Grid>
</ControlTemplate>
<!-- End: Previous button template -->
<!-- Start: Next button template -->
<ControlTemplate x:Key="NextButtonTemplate" TargetType="Button">
<Grid Cursor="Hand">
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="CommonStates">
<vsm:VisualState x:Name="Normal" />
<vsm:VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Storyboard.TargetName="TextColor" Storyboard.TargetProperty="Color" To="#FF73A9D8" Duration="0" />
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="TextColor" Storyboard.TargetProperty="Opacity" To=".5" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Rectangle Fill="#11E5EBF1" Stretch="Fill" Opacity="1"/>
<Grid>
<Path Margin="0,-6,14,0" Height="10" Width="6" VerticalAlignment="Center" HorizontalAlignment="Right" Stretch="Fill" Data="M282.875,231.875 L282.875,240.375 L288.625,236 z">
<Path.Fill>
<SolidColorBrush x:Name="TextColor" Color="#FF333333" />
</Path.Fill>
</Path>
</Grid>
</Grid>
</ControlTemplate>
<!-- End: Next button template -->
<!-- Start: Header button template -->
<ControlTemplate x:Key="HeaderButtonTemplate" TargetType="Button">
<Grid Cursor="Hand">
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="CommonStates">
<vsm:VisualState x:Name="Normal" />
<vsm:VisualState x:Name="MouseOver">
<Storyboard>
<ColorAnimation Storyboard.TargetName="TextColor" Storyboard.TargetProperty="Color" To="#FF73A9D8" Duration="0" />
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="buttonContent" Storyboard.TargetProperty="Opacity" To=".5" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<!-- This Border is new -->
<Border Padding="12 0"
CornerRadius="6">
<Border.Background>
<LinearGradientBrush StartPoint="0 0" EndPoint="0 1">
<GradientStop Offset="0" Color="#FFC4A0" />
<GradientStop Offset="1" Color="#FF9450" />
</LinearGradientBrush>
</Border.Background>
<ContentPresenter
x:Name="buttonContent"
Content="{TemplateBinding Content}"
ContentTemplate="{TemplateBinding ContentTemplate}"
Margin="1,4,1,9"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<TextElement.Foreground>
<SolidColorBrush x:Name="TextColor" Color="#FF333333"/>
</TextElement.Foreground>
</ContentPresenter>
</Border>
</Grid>
</ControlTemplate>
<!-- End: Header button template -->
</Grid.Resources>
<!-- Start: Previous button content -->
<Button x:Name="PART_PreviousButton"
Grid.Row="0" Grid.Column="0"
Template="{StaticResource PreviousButtonTemplate}"
Height="20" Width="28"
HorizontalAlignment="Left"
Focusable="False"
/>
<!-- End: Previous button content -->
<!-- Start: Header button content -->
<Button x:Name="PART_HeaderButton"
Grid.Row="0" Grid.Column="1"
Template="{StaticResource HeaderButtonTemplate}"
HorizontalAlignment="Center" VerticalAlignment="Center"
FontWeight="Bold" FontSize="10.5"
Focusable="False"
/>
<!-- End: Header button content -->
<!-- Start: Next button content -->
<Button x:Name="PART_NextButton"
Grid.Row="0" Grid.Column="2"
Height="20" Width="28"
HorizontalAlignment="Right"
Template="{StaticResource NextButtonTemplate}"
Focusable="False"
/>
<!-- End: Next button content -->
<!-- Start: Month Content Grid -->
<Grid x:Name="PART_MonthView" Grid.Row="1" Grid.ColumnSpan="3" Visibility="Visible" Margin="6,-1,6,6">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
</Grid>
<!-- End: Month Content Grid -->
<!-- End: Year Content Grid -->
<Grid x:Name="PART_YearView" Grid.Row="1" Grid.ColumnSpan="3" Visibility="Hidden" Margin="6,-3,7,6">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
</Grid>
<!-- End: Year Content Grid -->
</Grid>
</Border>
</Border>
<Rectangle x:Name="PART_DisabledVisual" Opacity="0" Visibility="Collapsed" Stretch="Fill" StrokeThickness="1" RadiusX="2" RadiusY="2" Stroke="{StaticResource DisabledColor}" Fill="{StaticResource DisabledColor}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter TargetName="PART_DisabledVisual" Property="Visibility" Value="Visible" />
</Trigger>
<DataTrigger Value="Year">
<DataTrigger.Binding>
<Binding Path="DisplayMode">
<Binding.RelativeSource>
<RelativeSource Mode="FindAncestor" AncestorType="{x:Type toolkit:Calendar}" />
</Binding.RelativeSource>
</Binding>
</DataTrigger.Binding>
<Setter TargetName="PART_MonthView" Property="Visibility" Value="Hidden" />
<Setter TargetName="PART_YearView" Property="Visibility" Value="Visible" />
</DataTrigger>
<DataTrigger Value="Decade">
<DataTrigger.Binding>
<Binding Path="DisplayMode">
<Binding.RelativeSource>
<RelativeSource Mode="FindAncestor" AncestorType="{x:Type toolkit:Calendar}" />
</Binding.RelativeSource>
</Binding>
</DataTrigger.Binding>
<Setter TargetName="PART_MonthView" Property="Visibility" Value="Hidden" />
<Setter TargetName="PART_YearView" Property="Visibility" Value="Visible" />
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The result of this example is the following image
But I want to custom the calendar become my own style as the following image
I have tried but I don't know how to do it, so someone can show me the way to to it?
Many thanks!
T&T

The above example has more the following styles:
<Style x:Key="PlaybackCalendarDayButton" TargetType="primitives:CalendarDayButton">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="primitives:CalendarDayButton">
<!-- This is new -->
<ControlTemplate.Resources>
<src:PlaybackCalendarConverter x:Key="conv" />
<src:PlaybackCalendarIsNotNullConverter x:Key="isNotNullConverter" />
</ControlTemplate.Resources>
<Grid ToolTip="{Binding Converter={StaticResource conv},
Mode=OneWay}">
<!-- Resume the copy -->
<vsm:VisualStateManager.VisualStateGroups>
<vsm:VisualStateGroup x:Name="CommonStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0:0:0.1" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="Normal" />
<vsm:VisualState x:Name="MouseOver">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Background" Storyboard.TargetProperty="Opacity" To=".5" Duration="0" />
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="Pressed">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Background" Storyboard.TargetProperty="Opacity" To=".5" Duration="0" />
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Background" Storyboard.TargetProperty="Opacity" To="0" Duration="0" />
<DoubleAnimation Storyboard.TargetName="NormalText" Storyboard.TargetProperty="Opacity" To=".35" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
<vsm:VisualStateGroup x:Name="SelectionStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="Unselected" />
<vsm:VisualState x:Name="Selected">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="SelectedBackground" Storyboard.TargetProperty="Opacity" To=".75" Duration="0" />
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
<vsm:VisualStateGroup x:Name="CalendarButtonFocusStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="CalendarButtonFocused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DayButtonFocusVisual" Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
<vsm:VisualState x:Name="CalendarButtonUnfocused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DayButtonFocusVisual" Storyboard.TargetProperty="Visibility" Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
<vsm:VisualStateGroup x:Name="ActiveStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="Active" />
<vsm:VisualState x:Name="Inactive">
<Storyboard>
<ColorAnimation Duration="0" Storyboard.TargetName="selectedText" Storyboard.TargetProperty="Color" To="#FF777777"></ColorAnimation>
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
<vsm:VisualStateGroup x:Name="DayStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="RegularDay" />
<vsm:VisualState x:Name="Today">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="TodayBackground" Storyboard.TargetProperty="Opacity" To="1" Duration="0" />
<ColorAnimation Duration="0" Storyboard.TargetName="selectedText" Storyboard.TargetProperty="Color" To="#FFFFFFFF"></ColorAnimation>
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
<vsm:VisualStateGroup x:Name="BlackoutDayStates">
<vsm:VisualStateGroup.Transitions>
<vsm:VisualTransition GeneratedDuration="0" />
</vsm:VisualStateGroup.Transitions>
<vsm:VisualState x:Name="NormalDay" />
<vsm:VisualState x:Name="BlackoutDay">
<Storyboard>
<DoubleAnimation Duration="0" Storyboard.TargetName="Blackout" Storyboard.TargetProperty="Opacity" To=".2"/>
</Storyboard>
</vsm:VisualState>
</vsm:VisualStateGroup>
</vsm:VisualStateManager.VisualStateGroups>
<Rectangle x:Name="TodayBackground" RadiusX="1" RadiusY="1" Opacity="0" Fill="#FFAAAAAA"/>
<Rectangle x:Name="SelectedBackground" RadiusX="1" RadiusY="1" Opacity="0" Fill="{TemplateBinding Background}"/>
<Rectangle x:Name="Background" RadiusX="1" RadiusY="1" Opacity="0" Fill="{TemplateBinding Background}"/>
<ContentPresenter
x:Name="NormalText"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
Margin="5,1,5,1"
>
<TextElement.Foreground>
<SolidColorBrush x:Name="selectedText" Color="#FF333333"/>
</TextElement.Foreground>
</ContentPresenter>
<Path x:Name="Blackout" Opacity="0" Margin="3" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" RenderTransformOrigin="0.5,0.5" Fill="#FF000000" Stretch="Fill" Data="M8.1772461,11.029181 L10.433105,11.029181 L11.700684,12.801641 L12.973633,11.029181 L15.191895,11.029181 L12.844727,13.999395 L15.21875,17.060919 L12.962891,17.060919 L11.673828,15.256231 L10.352539,17.060919 L8.1396484,17.060919 L10.519043,14.042364 z"/>
<Rectangle x:Name="DayButtonFocusVisual" Visibility="Collapsed" IsHitTestVisible="false" RadiusX="1" RadiusY="1" Stroke="#FF45D6FA"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsFocused" Value="True">
<Setter TargetName="DayButtonFocusVisual" Property="Visibility" Value="Visible" />
</Trigger>
<DataTrigger Binding="{Binding Converter={StaticResource isNotNullConverter}}" Value="{x:Null}">
<Setter TargetName="NormalText" Property="TextElement.Foreground" Value="Red"/>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
I must post it here because the question is limited by 30,000 characters.
Thanks!

Have you looked at : http://www.functionx.com/vcsharp/controls/monthcalendar.htm ?
Mainly:
Under the line separator, the numeric days of the month are listed. By default, the numeric days of the control display above a white background which is the Window system color. This color is controlled by the overridden BackColor property.
and
The Font Color of the Days of the Current Month
The numbers of the days of the month display in two colors. The real days of the selected month display, by default, in a black color as the WindowText system color. The color of these days is controlled by the overridden ForeColor property.

TimeUpDown focus minutes

I've written a small MouseEnter-Event for a TimeUpDown, to set the focus.
xaml:
<toolkit:TimeUpDown MouseEnter="TimeUpDown_MouseEnter" KeyDown="time_KeyDown" ValueChanged="time_Value_Changed" Value="{Binding Endtime, Mode=TwoWay,BindsDirectlyToSource=True}"/>
xaml.cs:
private void TimeUpDown_MouseEnter(object sender, MouseEventArgs e)
{
TimeUpDown picker = sender as TimeUpDown;
picker.Focus();
}
With this code, I focus (highlight) the complete time (eg 10:15 ... hrs and mins) for the TimeUpDown.
How can I only focus the minutes (eg 10:15) for the TimeUpDown???

The TextBox in the template of a TimeUpDown is not accessible, so I would recommend creating a style using a custom TextBox instead.
Edit complex templates in Expression Blend. I have copied the basic template of the TimeUpDown style below. As you can see it is not only very complex, but the TextBox is actually in a Template within a Template:
XAML (style part only)
<UserControl.Resources>
<Style x:Key="TimeUpDownStyle1" TargetType="toolkit:TimeUpDown">
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Height" Value="22"/>
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="MinWidth" Value="100"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="toolkit:TimeUpDown">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Pressed"/>
<VisualState x:Name="Disabled"/>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused"/>
<VisualState x:Name="Unfocused"/>
</VisualStateGroup>
<VisualStateGroup x:Name="TimeHintStates">
<VisualState x:Name="TimeHintOpenedUp">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="Visible"/>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="TimeHintVisualElement">
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="-23"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Height" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="22"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="TimeHintOpenedDown">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="Visible"/>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="TimeHintVisualElement">
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="0"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Height" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="22"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="TimeHintClosed">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteObjectKeyFrame KeyTime="00:00:20" Value="Collapsed"/>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[3].(TranslateTransform.Y)" Storyboard.TargetName="TimeHintVisualElement">
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="0"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Height" Storyboard.TargetName="TimeHintVisualElement">
<DiscreteDoubleKeyFrame KeyTime="00:00:00" Value="22"/>
<SplineDoubleKeyFrame KeySpline="0,0,0,1" KeyTime="00:00:00.200" Value="0"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="ParsingStates">
<VisualState x:Name="ValidTime">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="validicon">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="Visible"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="InvalidTime">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="invalidicon">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="Visible"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="EmptyTime">
<Storyboard>
<ObjectAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="emptyicon">
<DiscreteObjectKeyFrame KeyTime="00:00:00" Value="Visible"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Popup x:Name="TimeHintPopup" VerticalOffset="0">
<Border x:Name="TimeHintVisualElement" BorderBrush="Gray" BorderThickness="1" Background="White" HorizontalAlignment="Left" IsHitTestVisible="True" Visibility="Collapsed">
<Border.RenderTransform>
<TransformGroup>
<ScaleTransform/>
<SkewTransform/>
<RotateTransform/>
<TranslateTransform/>
</TransformGroup>
</Border.RenderTransform>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition MinWidth="15" Width="Auto"/>
</Grid.ColumnDefinitions>
<ContentControl Content="{TemplateBinding TimeHintContent}" Grid.Column="0" Foreground="#FF4A4A4A" FontSize="10" HorizontalAlignment="Right" IsHitTestVisible="False" IsTabStop="False" Margin="3" VerticalAlignment="Center"/>
<ContentControl x:Name="emptyicon" Grid.Column="1" IsHitTestVisible="False" IsTabStop="False" Margin="3" Visibility="Collapsed"/>
<ContentControl x:Name="validicon" Grid.Column="1" IsHitTestVisible="False" IsTabStop="False" Margin="3" Visibility="Collapsed"/>
<ContentControl x:Name="invalidicon" Grid.Column="1" IsHitTestVisible="False" IsTabStop="False" Visibility="Collapsed" VerticalAlignment="Center">
<Grid Height="13" VerticalAlignment="Bottom" Width="10">
<Path Data="F1 M 28.1143,29.4857L 28.1143,27.4286L 20.7612,13.0286L 19.3898,13.0286L 12.3429,27.4286L 12.3429,29.4857L 28.1143,29.4857 Z " HorizontalAlignment="Stretch" Height="11.833" StrokeStartLineCap="Round" Stretch="Fill" StrokeEndLineCap="Round" StrokeLineJoin="Bevel" VerticalAlignment="Top">
<Path.Fill>
<LinearGradientBrush EndPoint="-0.140331,0.460318" StartPoint="1.13883,0.460318">
<GradientStop Color="#FFF7F79F" Offset="0.123636"/>
<GradientStop Color="#FBFBFB7D" Offset="0.177662"/>
<GradientStop Color="#F6FFFF5B" Offset="0.24"/>
<GradientStop Color="#E7CAA709" Offset="0.52"/>
<GradientStop Color="#9ADABE0C" Offset="0.941376"/>
<GradientStop Color="#4DEBD60F" Offset="0.941818"/>
<GradientStop Color="#FBF6EC20" Offset="0.956364"/>
<GradientStop Color="#FFFFFF2F" Offset="0.963636"/>
</LinearGradientBrush>
</Path.Fill>
<Path.Stroke>
<LinearGradientBrush EndPoint="-0.102151,0.462591" StartPoint="1.10074,0.462591">
<GradientStop Color="#F6CAA709" Offset="0.0436364"/>
<GradientStop Color="#F3F7F34F" Offset="0.149091"/>
<GradientStop Color="#E7CAA709" Offset="0.825455"/>
<GradientStop Color="#E7967C07" Offset="0.967124"/>
<GradientStop Color="#E7625106" Offset="0.967273"/>
</LinearGradientBrush>
</Path.Stroke>
</Path>
<Path Data="F1 M 18.6937,17.3004L 22.2563,17.3004L 21.1313,23.6937L 19.8563,23.6937L 18.6937,17.3004 Z " Height="4.683" Margin="4.25,2.25,3.75,0" StrokeStartLineCap="Round" Stretch="Fill" StrokeEndLineCap="Round" Stroke="#FF1B1B54" StrokeThickness="0.3" StrokeLineJoin="Bevel" VerticalAlignment="Top">
<Path.Fill>
<LinearGradientBrush EndPoint="1.4,0.50126" StartPoint="-0.400002,0.50126">
<GradientStop Color="#FFF7F79F" Offset="0.123636"/>
<GradientStop Color="#FB8F8873" Offset="0.175974"/>
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<GradientStop Color="#E7271A47" Offset="0.534545"/>
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<GradientStop Color="#FBF6EC20" Offset="0.956364"/>
<GradientStop Color="#FFFFFF2F" Offset="0.963636"/>
</LinearGradientBrush>
</Path.Fill>
</Path>
<Path Data="F1 M 20.225,25.122L 20.725,25.122C 21.2773,25.122 21.725,25.5697 21.725,26.122L 21.725,26.872C 21.725,27.4243 21.2773,27.872 20.725,27.872L 20.225,27.872C 19.6727,27.872 19.225,27.4243 19.225,26.872L 19.225,26.122C 19.225,25.5697 19.6727,25.122 20.225,25.122 Z " Height="3.11" Margin="3.833,0,4.167,0.833" StrokeStartLineCap="Round" Stretch="Fill" StrokeEndLineCap="Round" Stroke="#FF1C1C50" StrokeThickness="0.3" StrokeLineJoin="Round" VerticalAlignment="Bottom">
<Path.Fill>
<LinearGradientBrush EndPoint="1.06,0.5" StartPoint="-0.0599991,0.5">
<GradientStop Color="#F6271A47" Offset="0.236364"/>
<GradientStop Color="#E7271A47" Offset="0.534545"/>
<GradientStop Color="#9A89782B" Offset="0.98135"/>
<GradientStop Color="#4DEBD60F" Offset="0.981818"/>
</LinearGradientBrush>
</Path.Fill>
</Path>
</Grid>
</ContentControl>
</Grid>
</Border>
</Popup>
<toolkit:ButtonSpinner x:Name="Spinner" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" HorizontalContentAlignment="Stretch" IsTabStop="False" MinWidth="35" Padding="{TemplateBinding Padding}" Style="{TemplateBinding SpinnerStyle}" VerticalContentAlignment="Stretch">
<TextBox x:Name="Text" AcceptsReturn="False" BorderThickness="0" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" MinWidth="20" TextAlignment="Right" TextWrapping="NoWrap" Text="{TemplateBinding Value}">
<TextBox.Style>
<Style TargetType="TextBox">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<ScrollViewer x:Name="ContentElement" BorderThickness="0" Padding="0"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</TextBox.Style>
</TextBox>
</toolkit:ButtonSpinner>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="TimePickerStyle1" TargetType="toolkit:TimePicker">
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="MinWidth" Value="125"/>
<Setter Property="Height" Value="22"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="PopupTemplate">
<Setter.Value>
<toolkit:TimePickerPopupTemplate>
<toolkit:ListTimePickerPopup/>
</toolkit:TimePickerPopupTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="toolkit:TimePicker">
<Grid x:Name="RootElement">
<Grid.Resources>
<ControlTemplate x:Key="PopupButtonTemplate" TargetType="ToggleButton">
<Grid FlowDirection="LeftToRight" Height="20" Width="20">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="00:00:00.1000000"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="Highlight">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.6"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="Highlight">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.8"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="DisabledVisualElement">
<SplineDoubleKeyFrame KeyTime="0" Value=".55"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="CheckStates">
<VisualState x:Name="Checked">
<Storyboard>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse">
<SplinePointKeyFrame KeyTime="00:00:00" Value="1.016,0.377"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse">
<SplinePointKeyFrame KeyTime="00:00:00" Value="-0.01,0.687"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Fill).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse">
<SplinePointKeyFrame KeyTime="00:00:00" Value="0.556,0.035"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Fill).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse">
<SplinePointKeyFrame KeyTime="00:00:00" Value="0.441,0.979"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse1">
<SplinePointKeyFrame KeyTime="00:00:00" Value="0.984,0.328"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse1">
<SplinePointKeyFrame KeyTime="00:00:00" Value="0.031,0.719"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse2">
<SplinePointKeyFrame KeyTime="00:00:00" Value="-0.047,0.516"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse2">
<SplinePointKeyFrame KeyTime="00:00:00" Value="1.016,0.422"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse3">
<SplinePointKeyFrame KeyTime="00:00:00" Value="1.062,0.375"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse3">
<SplinePointKeyFrame KeyTime="00:00:00" Value="0.031,0.688"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.StartPoint)" Storyboard.TargetName="ellipse4">
<SplinePointKeyFrame KeyTime="00:00:00" Value="1.031,0.281"/>
</PointAnimationUsingKeyFrames>
<PointAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetProperty="(Shape.Stroke).(LinearGradientBrush.EndPoint)" Storyboard.TargetName="ellipse4">
<SplinePointKeyFrame KeyTime="00:00:00" Value="-0.188,0.656"/>
</PointAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Unchecked"/>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused"/>
<VisualState x:Name="Unfocused"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid>
<Grid.Resources>
<LinearGradientBrush x:Key="Dot" EndPoint="1.025,0.434" StartPoint="-0.025,0.566">
<GradientStop Color="#FFC8C8C8"/>
<GradientStop Color="#FF19191A" Offset="1"/>
</LinearGradientBrush>
</Grid.Resources>
<Ellipse x:Name="Highlight" Margin="0,0,0,0" Opacity="0" Stroke="#FF0052CA" StrokeThickness="1"/>
<Ellipse x:Name="ellipse" Margin="1,1,1,1" Stroke="{StaticResource Dot}" StrokeThickness="0.75">
<Ellipse.Fill>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FFFFFFFF"/>
<GradientStop Color="#FFD7E3EC" Offset="0.80400002002716064"/>
<GradientStop Color="#FFFBFBFB" Offset="0.37099999189376831"/>
</LinearGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Ellipse x:Name="ellipse1" Height="2" Margin="8,2,8,0" Stroke="{StaticResource Dot}" VerticalAlignment="Top" Width="2">
<Ellipse.Fill>
<RadialGradientBrush>
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterY="0.5" CenterX="0.5" ScaleY="1.817" ScaleX="2.381"/>
<SkewTransform CenterY="0.5" CenterX="0.5"/>
<RotateTransform Angle="0.966" CenterY="0.5" CenterX="0.5"/>
<TranslateTransform X="-0.2" Y="0.087"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Color="#FF000000"/>
<GradientStop Color="#FFFB6A05" Offset="1"/>
<GradientStop Color="#FF4E4E4F" Offset="0.446"/>
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Ellipse x:Name="ellipse2" Height="2" Margin="8,0,8,2" Stroke="{StaticResource Dot}" VerticalAlignment="Bottom" Width="2">
<Ellipse.Fill>
<RadialGradientBrush>
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterY="0.5" CenterX="0.5" ScaleY="1.817" ScaleX="2.381"/>
<SkewTransform CenterY="0.5" CenterX="0.5"/>
<RotateTransform Angle="0.966" CenterY="0.5" CenterX="0.5"/>
<TranslateTransform X="-0.2" Y="0.087"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Color="#FF000000"/>
<GradientStop Color="#FFFB6A05" Offset="1"/>
<GradientStop Color="#FF4E4E4F" Offset="0.446"/>
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Ellipse x:Name="ellipse3" HorizontalAlignment="Left" Height="1" Margin="2,10,0,0" Stroke="{StaticResource Dot}" VerticalAlignment="Top" Width="1">
<Ellipse.Fill>
<RadialGradientBrush>
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterY="0.5" CenterX="0.5" ScaleY="1.817" ScaleX="2.381"/>
<SkewTransform CenterY="0.5" CenterX="0.5"/>
<RotateTransform Angle="0.966" CenterY="0.5" CenterX="0.5"/>
<TranslateTransform X="-0.2" Y="0.087"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Color="#FF000000"/>
<GradientStop Color="#FFFB6A05" Offset="1"/>
<GradientStop Color="#FF4E4E4F" Offset="0.446"/>
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Ellipse x:Name="ellipse4" HorizontalAlignment="Right" Height="1.421" Margin="0,10,2,0" Stroke="{StaticResource Dot}" VerticalAlignment="Top" Width="1.05">
<Ellipse.Fill>
<RadialGradientBrush>
<RadialGradientBrush.RelativeTransform>
<TransformGroup>
<ScaleTransform CenterY="0.5" CenterX="0.5" ScaleY="1.817" ScaleX="2.381"/>
<SkewTransform CenterY="0.5" CenterX="0.5"/>
<RotateTransform Angle="0.966" CenterY="0.5" CenterX="0.5"/>
<TranslateTransform X="-0.2" Y="0.087"/>
</TransformGroup>
</RadialGradientBrush.RelativeTransform>
<GradientStop Color="#FF000000"/>
<GradientStop Color="#FFFB6A05" Offset="1"/>
<GradientStop Color="#FF4E4E4F" Offset="0.446"/>
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<Path Data="M10.108397,6.5404582 L10.108397,10.415268 L13.538931,13.738435" Fill="{x:Null}" HorizontalAlignment="Left" Height="8.258" Margin="9,6,5,0" Stretch="Fill" VerticalAlignment="Top">
<Path.Stroke>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FF5B91D2"/>
<GradientStop Color="#FFC1570E" Offset="0.996"/>
</LinearGradientBrush>
</Path.Stroke>
</Path>
<Rectangle x:Name="DisabledVisualElement" Fill="#FFFFFFFF" IsHitTestVisible="false" Opacity="0" RadiusY="3" RadiusX="3"/>
</Grid>
</Grid>
</ControlTemplate>
</Grid.Resources>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Disabled"/>
<VisualState x:Name="Pressed"/>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused"/>
<VisualState x:Name="Unfocused"/>
</VisualStateGroup>
<VisualStateGroup x:Name="PopupStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.1" To="PopupOpened"/>
<VisualTransition GeneratedDuration="0:0:0.2" To="PopupClosed"/>
</VisualStateGroup.Transitions>
<VisualState x:Name="PopupOpened">
<Storyboard>
<DoubleAnimation To="1.0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PopupRoot"/>
</Storyboard>
</VisualState>
<VisualState x:Name="PopupClosed">
<Storyboard>
<DoubleAnimation To="0.0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PopupRoot"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<toolkit:TimeUpDown x:Name="TimeUpDown" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Culture="{TemplateBinding Culture}" Grid.Column="0" Format="{TemplateBinding Format}" Height="Auto" Maximum="{TemplateBinding Maximum}" Minimum="{TemplateBinding Minimum}" Padding="{TemplateBinding Padding}" Style="{StaticResource TimeUpDownStyle1}" SpinnerStyle="{TemplateBinding SpinnerStyle}" TimeParsers="{TemplateBinding TimeParsers}" TimeGlobalizationInfo="{TemplateBinding TimeGlobalizationInfo}"/>
<ToggleButton x:Name="DropDownToggle" Grid.Column="1" HorizontalAlignment="Center" Margin="3,0,0,0" Template="{StaticResource PopupButtonTemplate}" VerticalAlignment="Center"/>
<Popup x:Name="Popup">
<Border x:Name="PopupRoot" BorderBrush="#FF8d8b8b" BorderThickness="1">
<ContentControl x:Name="PopupPlaceHolder" HorizontalContentAlignment="Stretch" IsTabStop="False" VerticalContentAlignment="Stretch"/>
</Border>
</Popup>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>

If you have short format (hh:MM AM/PM), solution would be something like this:
int startIndex = picker.Text.Text.IndexOf(':');
picker.Text.SelectionStart = startIndex + 1;
picker.Text.SelectionLength = 2; // minutes have two digits
If you have other date format, then find index of colon that is just before the minutes.

WPF slider in disabled state after editing template

I used the latest Blend preview to create a style for the slider. When I run the application, the slider is always disabled. As soon as a remove the custom style, it is enabled again. I cannot see why this would be happening.
Template code generated by Blend is below:
<Style x:Key="SliderStyle1" TargetType="Slider">
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Maximum" Value="10"/>
<Setter Property="Minimum" Value="0"/>
<Setter Property="Value" Value="0"/>
<Setter Property="BorderBrush">
<Setter.Value>
<LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
<GradientStop Color="#FFA3AEB9" Offset="0"/>
<GradientStop Color="#FF8399A9" Offset="0.375"/>
<GradientStop Color="#FF718597" Offset="0.375"/>
<GradientStop Color="#FF617584" Offset="1"/>
</LinearGradientBrush>
</Setter.Value>
</Setter>
<Setter Property="IsTabStop" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Slider">
<Grid x:Name="Root">
<Grid.Resources>
<ControlTemplate x:Key="RepeatButtonTemplate">
<Grid x:Name="Root" Background="Transparent" Opacity="0"/>
</ControlTemplate>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="HorizontalTrackRectangleDisabledOverlay">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ThumbDisabledOverlay">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="VerticalTrackRectangleDisabledOverlay">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid x:Name="HorizontalTemplate" Background="{TemplateBinding Background}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Rectangle x:Name="TrackRectangle" Grid.ColumnSpan="3" Grid.Column="0" Fill="#FFE6EFF7" Height="3" Margin="5,0,5,0" RadiusY="1" RadiusX="1" Stroke="#FFA3AEB9" StrokeThickness="{TemplateBinding BorderThickness}"/>
<Rectangle x:Name="HorizontalTrackRectangleDisabledOverlay" Grid.ColumnSpan="3" Grid.Column="0" Fill="White" Height="3" Margin="5,0,5,0" Opacity=".55" RadiusY="1" RadiusX="1" Visibility="Collapsed"/>
<RepeatButton x:Name="HorizontalTrackLargeChangeDecreaseRepeatButton" Grid.Column="0" Height="18" IsTabStop="False" Template="{StaticResource RepeatButtonTemplate}"/>
<Thumb x:Name="HorizontalThumb" Grid.Column="1" Height="18" IsTabStop="True" Width="11"/>
<Rectangle x:Name="ThumbDisabledOverlay" Grid.Column="1" Fill="White" Opacity=".55" RadiusY="2" RadiusX="2" Visibility="Collapsed" Width="11"/>
<RepeatButton x:Name="HorizontalTrackLargeChangeIncreaseRepeatButton" Grid.Column="2" Height="18" IsTabStop="False" Template="{StaticResource RepeatButtonTemplate}"/>
</Grid>
<Grid x:Name="VerticalTemplate" Background="{TemplateBinding Background}" Visibility="Collapsed">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Rectangle Fill="#FFE6EFF7" Margin="0,5,0,5" RadiusY="1" Grid.Row="0" RadiusX="1" Grid.RowSpan="3" Stroke="#FFA3AEB9" StrokeThickness="{TemplateBinding BorderThickness}" Width="3"/>
<Rectangle x:Name="VerticalTrackRectangleDisabledOverlay" Fill="White" Margin="0,5,0,5" Opacity=".55" RadiusY="1" Grid.Row="0" RadiusX="1" Grid.RowSpan="3" Visibility="Collapsed" Width="3"/>
<RepeatButton x:Name="VerticalTrackLargeChangeDecreaseRepeatButton" IsTabStop="False" Grid.Row="2" Template="{StaticResource RepeatButtonTemplate}" Width="18"/>
<Thumb x:Name="VerticalThumb" Height="11" IsTabStop="True" Grid.Row="1" Width="18"/>
<RepeatButton x:Name="VerticalTrackLargeChangeIncreaseRepeatButton" IsTabStop="False" Grid.Row="0" Template="{StaticResource RepeatButtonTemplate}" Width="18"/>
</Grid>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Some of the Silverlight control templates work in WPF, while others do not. Slider is one of those controls.