<telerikDataGrid:DataGridTemplateColumn HeaderText="Age" 
                                        CanUserSort="True">
    <telerikDataGrid:DataGridTemplateColumn.CellContentTemplate>
        <DataTemplate>
            <Label Text="{Binding Age}" />
        </DataTemplate>
    </telerikDataGrid:DataGridTemplateColumn.CellContentTemplate>
    <telerikDataGrid:DataGridTemplateColumn.SortDescriptor>
        <telerikCommon:PropertySortDescriptor PropertyName="Age" SortOrder="Descending" />
    </telerikDataGrid:DataGridTemplateColumn.SortDescriptor>
</telerikDataGrid:DataGridTemplateColumn>

    <Grid RowDefinitions="*,100">

        <telerik:RadDataGrid x:Name="grdRegisters"
                             RowHeight="50"
                             Style="{StaticResource ReadOnlyGridStyle}"
                             ItemsSource="{Binding Registers}"
                             SelectionStyle="{StaticResource SelectedRowBackgroundStyle}"
                             RowBackgroundStyle="{StaticResource RowBackgroundStyle}"
                             AlternateRowBackgroundStyle="{StaticResource AltRowBackgroundStyle}"
                             SelectedItem="{Binding SelectedRegister, Mode=TwoWay}">
            <telerik:RadDataGrid.Columns>
                <telerik:DataGridTemplateColumn HeaderText=""
                                                SizeMode="Fixed"
                                                Width="50">
                    <telerik:DataGridTemplateColumn.CellContentTemplate>
                        <DataTemplate x:DataType="RegisterModel">
                            <Label FontFamily="FASolid" 
                                   HorizontalOptions="Center"
                                   VerticalOptions="Center"
                                   Text="&#xf005;" 
                                   IsVisible="{Binding IsCurrentRegister, Mode=OneTime}"/>
                        </DataTemplate>
                    </telerik:DataGridTemplateColumn.CellContentTemplate>
                </telerik:DataGridTemplateColumn>

                <telerik:DataGridTemplateColumn HeaderText="Shift Date">
                    <telerik:DataGridTemplateColumn.CellContentTemplate>
                        <DataTemplate x:DataType="RegisterModel">
                            <Label Style="{StaticResource GridCellLabelStyle}" 
                                   Text="{Binding Date, Converter={StaticResource ToLocalTimeConverter}, StringFormat='{}{0:d}'}"/>
                        </DataTemplate>
                    </telerik:DataGridTemplateColumn.CellContentTemplate>
                </telerik:DataGridTemplateColumn>

                <telerik:DataGridTemplateColumn HeaderText="Shift Name">
                    <telerik:DataGridTemplateColumn.CellContentTemplate>
                        <DataTemplate x:DataType="RegisterModel">
                            <Label Style="{StaticResource GridCellLabelStyle}" 
                                   Text="{Binding Shift.Name}"/>
                        </DataTemplate>
                    </telerik:DataGridTemplateColumn.CellContentTemplate>
                </telerik:DataGridTemplateColumn>

                <telerik:DataGridTemplateColumn HeaderText="Start Time">
                    <telerik:DataGridTemplateColumn.CellContentTemplate>
                        <DataTemplate x:DataType="RegisterModel">
                            <Label Style="{StaticResource GridCellLabelStyle}" 
                                   Text="{Binding StartTime, Converter={StaticResource ToLocalTimeConverter}, StringFormat='{}{0:t}'}"/>
                        </DataTemplate>
                    </telerik:DataGridTemplateColumn.CellContentTemplate>
                </telerik:DataGridTemplateColumn>

                <telerik:DataGridTemplateColumn HeaderText="End Time">
                    <telerik:DataGridTemplateColumn.CellContentTemplate>
                        <DataTemplate x:DataType="RegisterModel">
                            <Label Style="{StaticResource GridCellLabelStyle}" 
                                   Text="{Binding EndTime, Converter={StaticResource ToLocalTimeConverter}, StringFormat='{}{0:t}'}"/>
                        </DataTemplate>
                    </telerik:DataGridTemplateColumn.CellContentTemplate>
                </telerik:DataGridTemplateColumn>


            </telerik:RadDataGrid.Columns>
        </telerik:RadDataGrid>

        <HorizontalStackLayout Grid.Row="1">
            <Button Text="Resume"
                    IsEnabled="{Binding SelectedRegister, Converter={StaticResource IsNotNullConverter}}"
                    Command="{Binding ResumeShiftCommand}"/>

            <Button Text="Refresh"
                    Command="{Binding RefreshCommand}"/>

        </HorizontalStackLayout>
        
    </Grid>

<telerik:DataGridTextColumn.HeaderContentTemplate>
    <DataTemplate>
        <Label Text="your text"></Label>
    </DataTemplate>
</telerik:DataGridTextColumn.HeaderContentTemplate>

<telerik:RadDataGrid.GroupHeaderTemplate>
        <DataTemplate>
            <Label Text="{Binding Group.Key}"/>
        </DataTemplate>
</telerik:RadDataGrid.GroupHeaderTemplate>

<telerik:DataGridTextColumn HeaderText="Name" >
    <telerik:DataGridTextColumn.CellContentTemplate>
        <DataTemplate>
            <Label Text="{Binding Name}"/>
        </DataTemplate>
    </telerik:DataGridTextColumn.CellContentTemplate>
</telerik:DataGridTextColumn>