<ComboBox Name="cboCombo" IsReadOnly="True" IsEditable="True" Foreground="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=Foreground}" DropDownOpened="cboCombo_DropDownOpened" DropDownClosed="cboCombo_DropDownClosed">
            <ComboBox.Text>
                <MultiBinding Converter="{StaticResource DateTimeTextConverter}" Mode="OneWay">
                    <Binding RelativeSource="{RelativeSource FindAncestor,AncestorType={x:Type UserControl}}" Path="SelectedDateAndTime" Mode="OneWay" />
                    <Binding RelativeSource="{RelativeSource FindAncestor,AncestorType={x:Type UserControl}}" Path="ShowTime" />
                </MultiBinding>
            </ComboBox.Text>
            <ComboBoxItem IsSelected="True">
                <ComboBoxItem.Template>
                    <ControlTemplate>
                        <Grid>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="Auto" />
                            </Grid.RowDefinitions>

                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="*" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>

                            <DatePicker Grid.Row="0" Grid.Column="0" SelectedDate="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=SelectedDateAndTime}" SelectedDateChanged="BCDatePicker_SelectedDateChanged" />
                            <controls:TimePicker Grid.Row="0" Grid.Column="1" MouseUp="TimePicker_MouseUp" Loaded="TimePicker_Loaded" Time="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=SelectedDateAndTime,Mode=OneWay}" Visibility="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=ShowTime, Converter={StaticResource VisibilityConverter}}" />

                            <Button Grid.Row="1" Grid.Column="0" Content="Today" Click="Button_Click" />
                            <Button Grid.Row="1" Grid.Column="1" Content="Clear" Click="Button_Click_1" />

                            <Button Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2" Content="View Date Calculator" Click="Button_Click_2" Visibility="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=ShowDateCalculator,Mode=OneWay,Converter={StaticResource VisibilityConverter}}" />

                            <Label Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="2" Content="{Binding RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type UserControl}},Path=SelectedDateAndTime,Mode=OneWay,Converter={StaticResource HolidayDateConverter}}" Foreground="Red" />
                        </Grid>
                    </ControlTemplate>
                </ComboBoxItem.Template>
            </ComboBoxItem>
        </ComboBox>