Don't set MinHeight on the grid.

Let the grid resize for months with 4/5/6 rows to show.

Author: jdf3

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.Calendar.xaml

@@ -439,7 +439,7 @@
                                             <TranslateTransform X="0"/>
                                         </Border.RenderTransform>
                                     </Border>
-                                    <Grid x:Name="PART_MonthView" RenderTransformOrigin="0, 0.5" MinHeight="254">
+                                    <Grid x:Name="PART_MonthView" RenderTransformOrigin="0, 0.5">
                                         <Grid.RenderTransform>
                                             <TranslateTransform X="0" />
                                         </Grid.RenderTransform>