Removing the strikethrough line in CalendarView

[dend]

I am implementing a custom control based on CalendarView and have an undesired strikethrough line going through today, like this:

My CalendarViewDayItemStyle is defined as following:

<CalendarView.CalendarViewDayItemStyle>
    <Style TargetType="CalendarViewDayItem">
        <Setter Property="FontSize" Value="12" />
        <Setter Property="FontWeight" Value="ExtraLight" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate>
                    <Grid>
                        <StackPanel VerticalAlignment="Bottom">
                            <Grid
                                Padding="5"
                                Margin="4,0,4,4"
                                VerticalAlignment="Bottom">
                                <Grid.Background>
                                    <SolidColorBrush Color="{Binding RegularSeasonMarkerColor.Color}" Opacity="1"></SolidColorBrush>
                                </Grid.Background>
                                <TextBlock Text="{Binding RegularSeasonText}" TextDecorations="None"></TextBlock>
                            </Grid>

                            <Grid
                                Padding="5"
                                Margin="4,0,4,0"
                                VerticalAlignment="Bottom">
                                <Grid.Background>
                                    <SolidColorBrush Color="{Binding CSRSeasonMarkerColor.Color}" Opacity=".3"></SolidColorBrush>
                                </Grid.Background>
                                <TextBlock Text="{Binding CSRSeasonText}" TextDecorations="None"></TextBlock>
                            </Grid>
                        </StackPanel>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</CalendarView.CalendarViewDayItemStyle>

How can I remove the strikethrough without also changing IsTodayHighlighted, which would also remove the highlight for the current day?