diff --git a/src/Avalonia.Controls/ToolTip.cs b/src/Avalonia.Controls/ToolTip.cs
index 2f11746891..b458b15c64 100644
--- a/src/Avalonia.Controls/ToolTip.cs
+++ b/src/Avalonia.Controls/ToolTip.cs
@@ -204,13 +204,15 @@ namespace Avalonia.Controls
         private static void IsOpenChanged(AvaloniaPropertyChangedEventArgs e)
         {
             var control = (Control)e.Sender;
+            var newValue = (bool)e.NewValue;
+            ToolTip toolTip;
 
-            if ((bool)e.NewValue)
+            if (newValue)
             {
                 var tip = GetTip(control);
                 if (tip == null) return;
 
-                var toolTip = control.GetValue(ToolTipProperty);
+                toolTip = control.GetValue(ToolTipProperty);
                 if (toolTip == null || (tip != toolTip && tip != toolTip.Content))
                 {
                     toolTip?.Close();
@@ -223,9 +225,11 @@ namespace Avalonia.Controls
             }
             else
             {
-                var toolTip = control.GetValue(ToolTipProperty);
+                toolTip = control.GetValue(ToolTipProperty);
                 toolTip?.Close();
             }
+
+            toolTip?.UpdatePseudoClasses(newValue);
         }
 
         private void Open(Control control)
@@ -238,6 +242,9 @@ namespace Avalonia.Controls
             
             _popup.ConfigurePosition(control, GetPlacement(control), 
                 new Point(GetHorizontalOffset(control), GetVerticalOffset(control)));
+
+            WindowManagerAddShadowHintChanged(_popup, false);
+
             _popup.Show();
         }
 
@@ -250,5 +257,18 @@ namespace Avalonia.Controls
                 _popup = null;
             }
         }
+
+        private void WindowManagerAddShadowHintChanged(IPopupHost host, bool hint)
+        {
+            if (host is PopupRoot pr)
+            {
+                pr.PlatformImpl.SetWindowManagerAddShadowHint(hint);
+            }
+        }
+
+        private void UpdatePseudoClasses(bool newValue)
+        {
+            PseudoClasses.Set(":open", newValue);
+        }
     }
 }
diff --git a/src/Avalonia.Themes.Fluent/Accents/FluentBaseDark.xaml b/src/Avalonia.Themes.Fluent/Accents/FluentBaseDark.xaml
index 7a715bbde7..8233ecd02c 100644
--- a/src/Avalonia.Themes.Fluent/Accents/FluentBaseDark.xaml
+++ b/src/Avalonia.Themes.Fluent/Accents/FluentBaseDark.xaml
@@ -31,6 +31,10 @@
     <Color x:Key="SystemRevealListLowColor">#FF1D1D1D</Color>
     <Color x:Key="SystemRevealListMediumColor">#FF333333</Color>
     <!--<AcrylicBrush x:Key="SystemControlAcrylicWindowBrush" BackgroundSource="HostBackdrop" TintColor="{ThemeResource SystemChromeAltHighColor}" TintOpacity="0.8" FallbackColor="{ThemeResource SystemChromeMediumColor}" />-->
+    <!--<RevealBackgroundBrush x:Key="SystemControlTransparentRevealBackgroundBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBackgroundBrush" Color="Transparent" />
+    <!--<RevealBorderBrush x:Key="SystemControlTransparentRevealBorderBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBorderBrush" Color="Transparent" />
     
     <!-- Override system shape defaults -->
     <CornerRadius x:Key="ControlCornerRadius">2,2,2,2</CornerRadius>
@@ -312,5 +316,15 @@
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePointerOver" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePressed" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokeDisabled" ResourceKey="SystemControlTransparentBrush" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlForegroundChromeHighBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
   </Style.Resources>
 </Style>
diff --git a/src/Avalonia.Themes.Fluent/Accents/FluentBaseLight.xaml b/src/Avalonia.Themes.Fluent/Accents/FluentBaseLight.xaml
index 5c6286a0bc..b3285bebf5 100644
--- a/src/Avalonia.Themes.Fluent/Accents/FluentBaseLight.xaml
+++ b/src/Avalonia.Themes.Fluent/Accents/FluentBaseLight.xaml
@@ -31,6 +31,10 @@
     <Color x:Key="SystemRevealListLowColor">#FFE6E6E6</Color>
     <Color x:Key="SystemRevealListMediumColor">#FFCCCCCC</Color>
     <!--<AcrylicBrush x:Key="SystemControlAcrylicWindowBrush" BackgroundSource="HostBackdrop" TintColor="{ThemeResource SystemChromeAltHighColor}" TintOpacity="0.8" FallbackColor="{ThemeResource SystemChromeMediumColor}" />-->
+    <!--<RevealBackgroundBrush x:Key="SystemControlTransparentRevealBackgroundBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBackgroundBrush" Color="Transparent" />
+    <!--<RevealBorderBrush x:Key="SystemControlTransparentRevealBorderBrush" TargetTheme="Dark" Color="Transparent" FallbackColor="Transparent" />-->
+    <SolidColorBrush x:Key="SystemControlTransparentRevealBorderBrush" Color="Transparent" />
     
     <!-- Override system shape defaults -->
     <CornerRadius x:Key="ControlCornerRadius">2,2,2,2</CornerRadius>
@@ -313,5 +317,15 @@
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePointerOver" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokePressed" ResourceKey="SystemControlTransparentBrush" />
     <StaticResource x:Key="RadioButtonCheckGlyphStrokeDisabled" ResourceKey="SystemControlTransparentBrush" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlForegroundChromeHighBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
   </Style.Resources>
 </Style>
diff --git a/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml b/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml
index 7364c339f1..6412b2882e 100644
--- a/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml
+++ b/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesDark.xaml
@@ -290,6 +290,33 @@
     <SolidColorBrush x:Key="CheckBoxPressedBorderThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="CheckBoxPressedForegroundThemeBrush" Color="#FF000000" />
 
+    <!-- Resources for Calendar.xaml, CalendarButton.xaml, CalendarDayButton.xaml, CalendarItem.xaml -->
+    <StaticResource x:Key="CalendarViewFocusBorderBrush" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedHoverBorderBrush" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
+    <StaticResource x:Key="CalendarViewSelectedPressedBorderBrush" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedBorderBrush" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="CalendarViewHoverBorderBrush" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewPressedBorderBrush" ResourceKey="SystemControlHighlightBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewTodayForeground" ResourceKey="SystemControlHighlightAltChromeWhiteBrush" />
+    <StaticResource x:Key="CalendarViewBlackoutForeground" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewSelectedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewPressedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeForeground" ResourceKey="SystemControlHyperlinkBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeBackground" ResourceKey="SystemControlDisabledChromeMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewForeground" ResourceKey="SystemControlHyperlinkBaseMediumHighBrush" />
+    <StaticResource x:Key="CalendarViewBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewBorderBrush" ResourceKey="SystemControlForegroundChromeMediumBrush" />
+    <StaticResource x:Key="CalendarViewWeekDayForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPointerOver" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPressed" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBackground" ResourceKey="SystemControlTransparentRevealBackgroundBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBorderBrush" ResourceKey="SystemControlTransparentRevealBorderBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrush" ResourceKey="SystemControlTransparentBrush" />
     <!-- Resources for RadioButton.xaml -->
     <x:Double x:Key="RadioButtonBorderThemeThickness">1</x:Double>
     <StaticResource x:Key="RadioButtonForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
@@ -343,5 +370,16 @@
     <SolidColorBrush x:Key="RadioButtonPressedBorderThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="RadioButtonPressedForegroundThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="RadioButtonContentPointerOverForegroundThemeBrush" Color="{DynamicResource SystemColorHighlightTextColor}" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlTransientBorderBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
+    <Thickness x:Key="ToolTipBorderThemePadding">8,5,8,7</Thickness>
   </Style.Resources>
 </Style>
diff --git a/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml b/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml
index 15e157f573..65988f0e65 100644
--- a/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml
+++ b/src/Avalonia.Themes.Fluent/Accents/FluentControlResourcesLight.xaml
@@ -290,6 +290,33 @@
     <SolidColorBrush x:Key="CheckBoxPressedBorderThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="CheckBoxPressedForegroundThemeBrush" Color="#FFFFFFFF" />
 
+    <!-- Resources for Calendar.xaml, CalendarButton.xaml, CalendarDayButton.xaml, CalendarItem.xaml -->
+    <StaticResource x:Key="CalendarViewFocusBorderBrush" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedHoverBorderBrush" ResourceKey="SystemControlHighlightListAccentMediumBrush" />
+    <StaticResource x:Key="CalendarViewSelectedPressedBorderBrush" ResourceKey="SystemControlHighlightListAccentHighBrush" />
+    <StaticResource x:Key="CalendarViewSelectedBorderBrush" ResourceKey="SystemControlHighlightAccentBrush" />
+    <StaticResource x:Key="CalendarViewHoverBorderBrush" ResourceKey="SystemControlHighlightBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewPressedBorderBrush" ResourceKey="SystemControlHighlightBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewTodayForeground" ResourceKey="SystemControlHighlightAltChromeWhiteBrush" />
+    <StaticResource x:Key="CalendarViewBlackoutForeground" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewSelectedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewPressedForeground" ResourceKey="SystemControlHighlightBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeForeground" ResourceKey="SystemControlHyperlinkBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewOutOfScopeBackground" ResourceKey="SystemControlDisabledChromeMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewForeground" ResourceKey="SystemControlHyperlinkBaseMediumHighBrush" />
+    <StaticResource x:Key="CalendarViewBackground" ResourceKey="SystemControlBackgroundAltHighBrush" />
+    <StaticResource x:Key="CalendarViewBorderBrush" ResourceKey="SystemControlForegroundChromeMediumBrush" />
+    <StaticResource x:Key="CalendarViewWeekDayForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBackground" ResourceKey="SystemControlTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPointerOver" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundPressed" ResourceKey="SystemControlForegroundBaseMediumBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonForegroundDisabled" ResourceKey="SystemControlDisabledBaseMediumLowBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBackground" ResourceKey="SystemControlTransparentRevealBackgroundBrush" />
+    <StaticResource x:Key="CalendarViewCalendarItemRevealBorderBrush" ResourceKey="SystemControlTransparentRevealBorderBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrushPointerOver" ResourceKey="SystemControlHighlightTransparentBrush" />
+    <StaticResource x:Key="CalendarViewNavigationButtonBorderBrush" ResourceKey="SystemControlTransparentBrush" />
     <!-- Resources for RadioButton.xaml -->
     <x:Double x:Key="RadioButtonBorderThemeThickness">1</x:Double>
     <StaticResource x:Key="RadioButtonForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
@@ -343,5 +370,16 @@
     <SolidColorBrush x:Key="RadioButtonPressedBorderThemeBrush" Color="#FF000000" />
     <SolidColorBrush x:Key="RadioButtonPressedForegroundThemeBrush" Color="#FFFFFFFF" />
     <SolidColorBrush x:Key="RadioButtonContentPointerOverForegroundThemeBrush" Color="{DynamicResource SystemColorHighlightTextColor}" />
+
+    <!-- Resources for ToolTip.xaml -->
+    <x:Double x:Key="ToolTipContentThemeFontSize">12</x:Double>
+    <Thickness x:Key="ToolTipBorderThemeThickness">1</Thickness>
+    <StaticResource x:Key="ToolTipForeground" ResourceKey="SystemControlForegroundBaseHighBrush" />
+    <StaticResource x:Key="ToolTipBackground" ResourceKey="SystemControlBackgroundChromeMediumLowBrush" />
+    <StaticResource x:Key="ToolTipBorderBrush" ResourceKey="SystemControlTransientBorderBrush" />
+    <SolidColorBrush x:Key="ToolTipBackgroundThemeBrush" Color="#FFFFFFFF" />
+    <SolidColorBrush x:Key="ToolTipBorderThemeBrush" Color="#FF808080" />
+    <SolidColorBrush x:Key="ToolTipForegroundThemeBrush" Color="#FF666666" />
+    <Thickness x:Key="ToolTipBorderThemePadding">8,5,8,7</Thickness>
   </Style.Resources>
 </Style>
diff --git a/src/Avalonia.Themes.Fluent/Calendar.xaml b/src/Avalonia.Themes.Fluent/Calendar.xaml
index 6bbee4ef17..6ae334dbae 100644
--- a/src/Avalonia.Themes.Fluent/Calendar.xaml
+++ b/src/Avalonia.Themes.Fluent/Calendar.xaml
@@ -5,13 +5,14 @@
 // All other rights reserved.
 -->
 
-<Styles xmlns="https://github.com/avaloniaui">
+<Styles xmlns="https://github.com/avaloniaui">  
   <Style Selector="Calendar">
-    <!--<Setter Property="Focusable" Value="False" />-->
-    <Setter Property="BorderThickness" Value="{DynamicResource ThemeBorderThickness}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ThemeBorderHighBrush}" />
-    <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}" />
-    <Setter Property="HeaderBackground" Value="{DynamicResource ThemeAccentBrush2}" />
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewForeground}" />
+    <Setter Property="Background" Value="{DynamicResource CalendarViewBackground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewBorderBrush}" />
+    <Setter Property="BorderThickness" Value="1" />
+    <Setter Property="HorizontalAlignment" Value="Left" />
+    <Setter Property="VerticalAlignment" Value="Center" />
     <Setter Property="Template">
       <ControlTemplate>
         <StackPanel Name="Root"
@@ -28,4 +29,4 @@
       </ControlTemplate>
     </Setter>
   </Style>
-</Styles>
\ No newline at end of file
+</Styles>
diff --git a/src/Avalonia.Themes.Fluent/CalendarButton.xaml b/src/Avalonia.Themes.Fluent/CalendarButton.xaml
index 3314534b3b..87082ef21e 100644
--- a/src/Avalonia.Themes.Fluent/CalendarButton.xaml
+++ b/src/Avalonia.Themes.Fluent/CalendarButton.xaml
@@ -7,75 +7,115 @@
 
 <Styles xmlns="https://github.com/avaloniaui">
   <Style Selector="CalendarButton">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeBorderHighBrush}" />
-    <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}" />
-    <Setter Property="FontSize" Value="{DynamicResource FontSizeSmall}" />
-    <Setter Property="HorizontalContentAlignment" Value="Center" />
-    <Setter Property="VerticalContentAlignment" Value="Center" />
-    <Setter Property="MinWidth" Value="37" />
-    <Setter Property="MinHeight" Value="38" />
-    <Setter Property="Focusable" Value="False"/>
+    <Setter Property="ClickMode" Value="Release"/>
+    <Setter Property="MinWidth" Value="40"/>
+    <Setter Property="MinHeight" Value="40"/>
+    <Setter Property="Margin" Value="1"/>
+    <Setter Property="Padding" Value="0,0,0,4"/>
+    <!--These are actually set on the CalendarView in WinUI-->
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewCalendarItemForeground}"/>
+    <Setter Property="Background" Value="{DynamicResource CalendarViewCalendarItemRevealBackground}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewCalendarItemRevealBorderBrush}"/>
+    <Setter Property="BorderThickness" Value="2"/>
+    <Setter Property="FontSize" Value="20"/>
+    <Setter Property="ClipToBounds" Value="False"/>
+    <Setter Property="HorizontalContentAlignment" Value="Center"/>
+    <Setter Property="VerticalContentAlignment" Value="Center"/>
     <Setter Property="Template">
       <ControlTemplate>
-        <Grid>
+        <Panel>
+          <!-- To mimic WinUI SystemFocusVisual, Focus visual is drawn outside the bounds of the item -->
+          <Border Name="Root" Background="{TemplateBinding Background}"
+                  BorderThickness="0" ClipToBounds="True">
 
-          <Rectangle Name="SelectedBackground"
-                     Opacity="0.75"
-                     Fill="{TemplateBinding Background}"/>
+            <ContentControl Name="Content"
+                  ContentTemplate="{TemplateBinding ContentTemplate}"
+                  Content="{TemplateBinding Content}"
+                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                  FontSize="{TemplateBinding FontSize}"
+                  Margin="{TemplateBinding Padding}"/>
 
-          <Rectangle Name="Background"
-                     Opacity="0.5"
-                     Fill="{TemplateBinding Background}"/>
+          </Border>
 
-          <!--Focusable="False"-->
-          <ContentControl Name="Content"
-                          Foreground="{TemplateBinding Foreground}"
-                          ContentTemplate="{TemplateBinding ContentTemplate}"
-                          Content="{TemplateBinding Content}"
-                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
-                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
-                          FontSize="{TemplateBinding FontSize}"
-                          Margin="1,0,1,1"/>
+          <!-- Drawn Border should render on top of background to preserve the 1px
+                        margin between items-->
+          <Border Name="Border"
+                  BorderThickness="2"
+                  BorderBrush="{TemplateBinding BorderBrush}"/>
 
-          <Rectangle Name="FocusVisual"
-                     StrokeThickness="1"
-                     Stroke="{DynamicResource HighlightBrush}"
-                     IsHitTestVisible="False"/>
-
-        </Grid>
+          <!--Removed for now...WinUI doesn't have selection follow focus, and only uses 
+              focus visual w/ keyboard focus
+          <Border Name="FocusVisual" BorderThickness="2"
+                     BorderBrush="{DynamicResource SystemControlHighlightBaseHighBrush}"
+                     IsHitTestVisible="False"
+                     Margin="-2"  CornerRadius="{DynamicResource ControlCornerRadius}"/>-->
+        </Panel>
       </ControlTemplate>
     </Setter>
   </Style>
-
-  <Style Selector="CalendarButton /template/ Rectangle#Background">
+  <!--<Style Selector="CalendarButton /template/ Border#FocusVisual">
     <Setter Property="IsVisible" Value="False"/>
+  </Style>-->
+
+  <Style Selector="CalendarButton:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarButton:pointerover /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
-  </Style>
-  <Style Selector="CalendarButton:pressed /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
+  <Style Selector="CalendarButton:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewPressedBorderBrush}"/>
   </Style>
 
-  <Style Selector="CalendarButton /template/ Rectangle#SelectedBackground">
-    <Setter Property="IsVisible" Value="False"/>
+  <!-- Adjusted :selected to look like :today from DayItem -->
+  <Style Selector="CalendarButton:selected /template/ Border#Root">
+    <Setter Property="Background" Value="{DynamicResource SystemAccentBrush}"/>
   </Style>
-  <Style Selector="CalendarButton:selected /template/ Rectangle#SelectedBackground">
-    <Setter Property="IsVisible" Value="True"/>
+  <Style Selector="CalendarButton:selected /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedBorderBrush}"/>
+  </Style>
+  <Style Selector="CalendarButton:selected:pointerover /template/ Border#Root">
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:selected:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark1}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:selected:pressed /template/ Border#Root">
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
+  </Style>
+  <Style Selector="CalendarButton:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark2}"/>
+    </Setter>
+  </Style>
+
+  <Style Selector="CalendarButton:selected /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewTodayForeground}"/>
+    <Setter Property="FontWeight" Value="SemiBold"/>
   </Style>
 
-  <Style Selector="CalendarButton /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
+  <!-- WinUI calls this OutOfFocus -->
+  <Style Selector="CalendarButton:inactive /template/ Border#Root">
+    <!-- These are probably set in code, but consistent -->
+    <Setter Property="Background" Value="{DynamicResource CalendarViewOutOfScopeBackground}"/>
   </Style>
   <Style Selector="CalendarButton:inactive /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundLowBrush}"/>
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewOutOfScopeForeground}"/>
   </Style>
 
-
-  <Style Selector="CalendarButton /template/ Rectangle#FocusVisual">
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarButton:blackout /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewBlackoutForeground}"/>
   </Style>
-  <Style Selector="CalendarButton:btnfocused /template/ Rectangle#FocusVisual">
-    <Setter Property="IsVisible" Value="True"/>
+
+  <!--<Style Selector="CalendarButton:dayfocused /template/ Border#FocusVisual">
+            <Setter Property="IsVisible" Value="True"/>
+      </Style>-->
+
+  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
   </Style>
 </Styles>
diff --git a/src/Avalonia.Themes.Fluent/CalendarDayButton.xaml b/src/Avalonia.Themes.Fluent/CalendarDayButton.xaml
index 2d79e62a75..ff72044c93 100644
--- a/src/Avalonia.Themes.Fluent/CalendarDayButton.xaml
+++ b/src/Avalonia.Themes.Fluent/CalendarDayButton.xaml
@@ -7,110 +7,110 @@
 
 <Styles xmlns="https://github.com/avaloniaui">
   <Style Selector="CalendarDayButton">
-    <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}" />
-    <Setter Property="FontSize" Value="{DynamicResource FontSizeSmall}" />
-    <Setter Property="HorizontalContentAlignment" Value="Center" />
-    <Setter Property="VerticalContentAlignment" Value="Center" />
-    <Setter Property="MinWidth" Value="5" />
-    <Setter Property="MinHeight" Value="5" />
-    <Setter Property="Focusable" Value="False"/>
+    <Setter Property="ClickMode" Value="Release"/>
+    <Setter Property="MinWidth" Value="40"/>
+    <Setter Property="MinHeight" Value="40"/>
+    <Setter Property="Margin" Value="1"/>
+    <Setter Property="Padding" Value="0,0,0,4"/>
+    <!--These are actually set on the CalendarView in WinUI-->
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewCalendarItemForeground}"/>
+    <Setter Property="Background" Value="{DynamicResource CalendarViewCalendarItemRevealBackground}"/>
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewCalendarItemRevealBorderBrush}"/>
+    <Setter Property="BorderThickness" Value="2"/>
+    <Setter Property="FontSize" Value="20"/>
+    <Setter Property="ClipToBounds" Value="False"/>
+    <Setter Property="HorizontalContentAlignment" Value="Center"/>
+    <Setter Property="VerticalContentAlignment" Value="Center"/>
     <Setter Property="Template">
       <ControlTemplate>
-        <Panel Background="Transparent">
-
-          <Rectangle Name="TodayBackground"
-                     Fill="{DynamicResource HighlightBrush}"/>
-
-          <Rectangle Name="SelectedBackground"
-                     Opacity="0.75"
-                     Fill="{TemplateBinding Background}"/>
-
-          <Rectangle Name="Background"
-                     Opacity="0.5"
-                     Fill="{TemplateBinding Background}"/>
-
-          <ContentControl Name="Content"
-                          ContentTemplate="{TemplateBinding ContentTemplate}"
-                          Content="{TemplateBinding Content}"
-                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
-                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
-                          FontSize="{TemplateBinding FontSize}"
-                          Margin="5,1,5,1"/>
-
-          <Path Name="BlackoutVisual"
-                Margin="3"
-                HorizontalAlignment="Stretch"
-                VerticalAlignment="Stretch"
-                RenderTransformOrigin="0.5,0.5"
-                Fill="{DynamicResource ThemeForegroundBrush}"
-                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 Name="FocusVisual"
-                     StrokeThickness="1"
-                     Stroke="{DynamicResource HighlightBrush}"
-                     IsHitTestVisible="False"/>
-
+        <Panel>
+          <!-- To mimic WinUI SystemFocusVisual, Focus visual is drawn outside the bounds of the item -->
+          <Border Name="Root" Background="{TemplateBinding Background}"
+                  BorderThickness="0" ClipToBounds="True">
+
+            <ContentControl Name="Content"
+                  ContentTemplate="{TemplateBinding ContentTemplate}"
+                  Content="{TemplateBinding Content}"
+                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                  VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                  FontSize="{TemplateBinding FontSize}"
+                  Margin="{TemplateBinding Padding}"/>
+
+          </Border>
+
+          <!-- Drawn Border should render on top of background to preserve the 1px
+                        margin between items-->
+          <Border Name="Border"
+                  BorderThickness="2"
+                  BorderBrush="{TemplateBinding BorderBrush}"/>
+
+          <!--Removed for now...WinUI doesn't have selection follow focus, and only uses 
+              focus visual w/ keyboard focus
+                <Border Name="FocusVisual" BorderThickness="2"
+                            BorderBrush="{DynamicResource SystemControlHighlightBaseHighBrush}"
+                            IsHitTestVisible="False"
+                            Margin="-2"  CornerRadius="2"/>-->
         </Panel>
       </ControlTemplate>
     </Setter>
   </Style>
-
-  <Style Selector="CalendarDayButton /template/ Rectangle#Background">
+  <!--<Style Selector="CalendarDayButton /template/ Border#FocusVisual">
     <Setter Property="IsVisible" Value="False"/>
-  </Style>
-  <Style Selector="CalendarDayButton:pointerover /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
-  </Style>
-  <Style Selector="CalendarDayButton:pressed /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="True"/>
-  </Style>
+  </Style>-->
 
-  <Style Selector="CalendarDayButton /template/ Rectangle#SelectedBackground">
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarDayButton:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:selected /template/ Rectangle#SelectedBackground">
-    <Setter Property="IsVisible" Value="True"/>
+  <Style Selector="CalendarDayButton:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewPressedBorderBrush}"/>
   </Style>
-
-  <Style Selector="CalendarDayButton /template/ ContentControl#Content">
-    <Setter Property="Opacity" Value="1"/>
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundBrush}"/>
+  <Style Selector="CalendarDayButton:selected /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:disabled /template/ Rectangle#Background">
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarDayButton:selected:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedHoverBorderBrush}"/>
   </Style>
-  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
-    <Setter Property="Opacity" Value="0.3"/>
+  <Style Selector="CalendarDayButton:selected:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewSelectedPressedBorderBrush}"/>
   </Style>
 
-  <Style Selector="CalendarDayButton /template/ Rectangle#FocusVisual">
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarDayButton:today /template/ Border#Root">
+    <!-- These are probably set in code, but consistent -->
+    <Setter Property="Background">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColor}"/>
+    </Setter>
   </Style>
-  <Style Selector="CalendarDayButton:dayfocused /template/ Rectangle#FocusVisual">
-    <Setter Property="IsVisible" Value="True"/>
+  <Style Selector="CalendarDayButton:today:pointerover /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark1}"/>
+    </Setter>
   </Style>
-
-  <Style Selector="CalendarDayButton /template/ Rectangle#TodayBackground">
-    <Setter Property="IsVisible" Value="False"/>
+  <Style Selector="CalendarDayButton:today:pressed /template/ Border#Border">
+    <Setter Property="BorderBrush">
+      <SolidColorBrush Color="{DynamicResource SystemAccentColorDark2}"/>
+    </Setter>
   </Style>
-  <Style Selector="CalendarDayButton:today /template/ Rectangle#TodayBackground">
-    <Setter Property="IsVisible" Value="True"/>
+  <Style Selector="CalendarDayButton:today /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewTodayForeground}"/>
+    <Setter Property="FontWeight" Value="SemiBold"/>
   </Style>
 
-
-  <Style Selector="CalendarDayButton:inactive /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeForegroundLowBrush}"/>
+  <!-- WinUI calls this OutOfFocus -->
+  <Style Selector="CalendarDayButton:inactive /template/ Border#Root">
+    <Setter Property="Background" Value="{DynamicResource CalendarViewOutOfScopeBackground}"/>
   </Style>
-  <Style Selector="CalendarDayButton:today /template/ ContentControl#Content">
-    <Setter Property="Foreground" Value="{DynamicResource ThemeControlLowBrush}"/>
+  <Style Selector="CalendarDayButton:inactive /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewOutOfScopeForeground}"/>
   </Style>
 
-  <Style Selector="CalendarDayButton /template/ Path#BlackoutVisual">
-    <Setter Property="Opacity" Value="0"/>
+  <Style Selector="CalendarDayButton:blackout /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewBlackoutForeground}"/>
   </Style>
-  <Style Selector="CalendarDayButton:blackout /template/ Path#BlackoutVisual">
-    <Setter Property="Opacity" Value="0.3"/>
-  </Style>  
 
+  <!--<Style Selector="CalendarDayButton:dayfocused /template/ Border#FocusVisual">
+            <Setter Property="IsVisible" Value="True"/>
+      </Style>-->
+  <Style Selector="CalendarDayButton:disabled /template/ ContentControl#Content">
+    <Setter Property="Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
+  </Style>
 </Styles>
diff --git a/src/Avalonia.Themes.Fluent/CalendarItem.xaml b/src/Avalonia.Themes.Fluent/CalendarItem.xaml
index dfd89ed82f..df17da84dc 100644
--- a/src/Avalonia.Themes.Fluent/CalendarItem.xaml
+++ b/src/Avalonia.Themes.Fluent/CalendarItem.xaml
@@ -8,176 +8,127 @@
 <Styles xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
   <Style Selector="CalendarItem">
-    <Setter Property="Template">
-      <ControlTemplate>
-        <Panel>
-          <Border BorderThickness="{TemplateBinding BorderThickness}"
-                  BorderBrush="{TemplateBinding BorderBrush}"
-                  Background="{TemplateBinding Background}"
-                  Margin="0,2,0,2"
-                  CornerRadius="1">
-
-            <Border CornerRadius="1"
-                    BorderBrush="{DynamicResource ThemeBackgroundBrush}"
-                    BorderThickness="2">
-              <Grid>
-                <Grid.RowDefinitions>
-                  <RowDefinition Height="Auto" />
-                  <RowDefinition Height="*" />
-                </Grid.RowDefinitions>
-                <Grid.ColumnDefinitions>
-                  <ColumnDefinition Width="Auto" />
-                  <ColumnDefinition Width="*" />
-                  <ColumnDefinition Width="Auto" />
-                </Grid.ColumnDefinitions>
-
-                <Grid.Styles>
-                  <Style Selector="Button.CalendarHeader">
-                    <Setter Property="Cursor" Value="Hand"/>
-                    <Setter Property="Background" Value="Transparent"/>
-                    <Setter Property="BorderThickness" Value="0"/>
-                  </Style>
-                    <Style Selector="Button.CalendarHeader:pressed  /template/ ContentPresenter">
-                    <Setter Property="Background" Value="Transparent"/>
-                  </Style>
-
-                  <Style Selector="Button.CalendarNavigation">
-                    <Setter Property="Height" Value="20"/>
-                    <Setter Property="Width" Value="28"/>
-                  </Style>
-                  <Style Selector="Button.CalendarNavigation > Path">
-                    <Setter Property="Fill" Value="{DynamicResource ThemeForegroundBrush}"/>
-                  </Style>
-                  <Style Selector="Button.CalendarNavigation:pointerover > Path">
-                    <Setter Property="Fill" Value="{DynamicResource HighlightBrush}"/>
-                  </Style>
-
-                  <Style Selector="Button#HeaderButton:pointerover">
-                    <Setter Property="Foreground" Value="{DynamicResource HighlightBrush}"/>
-                  </Style>
-                </Grid.Styles>
-
-                <Rectangle Grid.ColumnSpan="3"
-                           Fill="{TemplateBinding HeaderBackground}"
-                           Stretch="Fill"
-                           VerticalAlignment="Top"
-                           Height="22"/>
-
-                <Button Name="PreviousButton"
-                        Classes="CalendarHeader CalendarNavigation"
-                        IsVisible="False"
-                        HorizontalAlignment="Left">
-
-                  <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" />
-                  
-                </Button>
-                
-                <Button Name="HeaderButton"
-                        Classes="CalendarHeader"
-                        Grid.Column="1"
-                        FontWeight="Bold"
-                        FontSize="10.5"
-                        HorizontalAlignment="Center"
-                        VerticalAlignment="Center" 
-                        Padding="1,5,1,9"/>
-
-                <Button Name="NextButton"
-                        Classes="CalendarHeader CalendarNavigation"
-                        Grid.Column="2"
-                        IsVisible="False"
-                        HorizontalAlignment="Right" >
-
-                  <Path Margin="0,-6,14,0"
-                        Height="10"
-                        Width="6"
-                        Stretch="Fill"
-                        VerticalAlignment="Center"
-                        HorizontalAlignment="Right"
-                        Data="M282.875,231.875 L282.875,240.375 L288.625,236 z" />
-                  
-                </Button>
-
-                <Grid Name="MonthView"
-                      Grid.Row="1"
-                      Grid.ColumnSpan="3"
-                      IsVisible="False"
-                      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>
-
-                <Grid Name="YearView"
-                      Grid.Row="1"
-                      Grid.ColumnSpan="3"
-                      IsVisible="False"
-                      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>
-
-              </Grid>
-            </Border>
-          </Border>
-
-
-          <Rectangle Name="DisabledVisual"
-                     Stretch="Fill"
-                     Fill="{DynamicResource ThemeControlLowBrush}"
-                     Opacity="{DynamicResource ThemeDisabledOpacity}"
-                     Margin="0,2,0,2" />
-
-        </Panel>
-      </ControlTemplate>
-    </Setter>
     <Setter Property="DayTitleTemplate">
       <Template>
-        <TextBlock FontWeight="Bold"
-                   FontSize="9.5"
-                   Margin="0,4,0,4"
+        <TextBlock Text="{Binding}"
                    HorizontalAlignment="Center"
                    VerticalAlignment="Center"
-                   Text="{Binding}" />
+                   FontSize="12"/>
       </Template>
-
+    </Setter>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border BorderThickness="{TemplateBinding BorderThickness}"
+                Background="{TemplateBinding Background}"
+                BorderBrush="{TemplateBinding BorderBrush}"
+                CornerRadius="{DynamicResource ControlCornerRadius}">
+          <Border.Styles>
+            <Style Selector="Button.CalendarHeader">
+              <Setter Property="HorizontalAlignment" Value="Stretch" />
+              <Setter Property="VerticalAlignment" Value="Stretch" />
+              <Setter Property="FontSize" Value="20" />
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+              <Setter Property="Template">
+                <ControlTemplate>
+                  <!-- HCA was changed here to ensure nav arrows display correctly -->
+                  <ContentPresenter Name="Text" Background="{TemplateBinding Background}"
+                                    BorderBrush="{DynamicResource CalendarViewNavigationButtonBorderBrush}"
+                                    BorderThickness="{TemplateBinding BorderThickness}"
+                                    Content="{TemplateBinding Content}"
+                                    Margin="{TemplateBinding Padding}"
+                                    HorizontalContentAlignment="Stretch"
+                                    VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" />
+                </ControlTemplate>
+              </Setter>
+            </Style>
+            <Style Selector="Button.CalendarNavigation > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewForeground}"/>
+            </Style>
+            <Style Selector="Button.CalendarNavigation:pointerover > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewNavigationButtonForegroundPointerOver}"/>
+            </Style>
+            <Style Selector="Button.CalendarNavigation:pressed > Path">
+              <Setter Property="Stroke" Value="{DynamicResource CalendarViewNavigationButtonForegroundPressed}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:pointerover /template/ ContentPresenter#Text">
+              <Setter Property="BorderBrush" Value="{DynamicResource CalendarViewNavigationButtonBorderBrushPointerOver}" />
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewNavigationButtonForegroundPointerOver}"/>
+              <!-- Prevent base button template:pointerover from overriding background here -->
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:pressed /template/ ContentPresenter#Text">
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewNavigationButtonForegroundPressed}"/>
+              <!-- Prevent base button template:pointerover from overriding background here -->
+              <Setter Property="Background" Value="{DynamicResource CalendarViewNavigationButtonBackground}"/>
+            </Style>
+            <Style Selector="Button.CalendarHeader:disabled /template/ ContentPresenter">
+              <Setter Property="TextBlock.Foreground" Value="{DynamicResource CalendarViewWeekDayForegroundDisabled}"/>
+            </Style>
+          </Border.Styles>
+          <!--  To keep calendar from resizing when switching DisplayMode
+                In WinUI Min-Width from TemplateSettings
+                basically...MinWidth of DayItem = 40, 40 * 7 = 280 + margins/padding = ~294
+                Viewport height is set from # of rows displayed (2-8) in Month mode, = ~290 for 6 weeks (+ day names)
+                -->
+          <Grid VerticalAlignment="Stretch" HorizontalAlignment="Stretch" RowDefinitions="40,*" MinWidth="294">
+            <Grid ColumnDefinitions="5*,*,*">
+              <Button Name="HeaderButton" Classes="CalendarHeader" Foreground="{TemplateBinding Foreground}" Padding="12,0,0,0" HorizontalContentAlignment="Left" />
+              <Button Name="PreviousButton" Grid.Column="1" Classes="CalendarHeader CalendarNavigation" Foreground="{TemplateBinding Foreground}" Padding="1" HorizontalContentAlignment="Left">
+                <!--Path mimics Segoe MDL2 Assets font glyph used in WinUI-->
+                <Path StrokeThickness="1.5" Data="M 0,9 L 9,0 L 18,9"  HorizontalAlignment="Center" VerticalAlignment="Center"/>
+              </Button>
+              <Button Name="NextButton" Grid.Column="2" Classes="CalendarHeader CalendarNavigation" Foreground="{TemplateBinding Foreground}" Padding="1" HorizontalContentAlignment="Left">
+                <!--Path mimics Segoe MDL2 Assets font glyph used in WinUI-->
+                <Path StrokeThickness="1.5" Data="M 0,0 L 9,9 L 18,0" HorizontalAlignment="Center" VerticalAlignment="Center"/>
+              </Button>
+            </Grid>
+            <Border Name="BackgroundLayer" Background="{TemplateBinding BorderBrush}" Grid.Row="1" />
+            <Grid Name="MonthView" Grid.Row="1" IsVisible="False" MinHeight="290" >
+              <Grid.RowDefinitions>
+                <!--This should always be the week day names??-->
+                <RowDefinition Height="38" />
+                <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>
+            <Grid Name="YearView" MinHeight="290"
+                    Grid.Row="1" IsVisible="False">
+              <Grid.RowDefinitions>
+                <RowDefinition Height="*" />
+                <RowDefinition Height="*" />
+                <RowDefinition Height="*" />
+              </Grid.RowDefinitions>
+              <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+              </Grid.ColumnDefinitions>
+            </Grid>
+
+          </Grid>
+
+        </Border>
+      </ControlTemplate>
     </Setter>
   </Style>
 
-  <Style Selector="CalendarItem /template/ Rectangle#DisabledVisual">
-    <Setter Property="IsVisible" Value="False"/>
-  </Style>
-  <Style Selector="CalendarItem:calendardisabled /template/ Rectangle#DisabledVisual">
-    <Setter Property="IsVisible" Value="True"/>
+  <!-- BackgroundLayer shouldn't show in the week day names row-->
+  <Style Selector="Calendar[DisplayMode=Month] CalendarItem /template/ Border#BackgroundLayer">
+    <Setter Property="Margin" Value="0,38,0,0"/>
   </Style>
   
 </Styles>
diff --git a/src/Avalonia.Themes.Fluent/ToolTip.xaml b/src/Avalonia.Themes.Fluent/ToolTip.xaml
index 1fc0202dd3..cf6f32f9bc 100644
--- a/src/Avalonia.Themes.Fluent/ToolTip.xaml
+++ b/src/Avalonia.Themes.Fluent/ToolTip.xaml
@@ -1,17 +1,78 @@
-<Style xmlns="https://github.com/avaloniaui" Selector="ToolTip">
-  <Setter Property="Background" Value="{DynamicResource ThemeBackgroundBrush}"/>
-  <Setter Property="BorderBrush" Value="{DynamicResource ThemeBorderMidBrush}"/>
-  <Setter Property="BorderThickness" Value="{DynamicResource ThemeBorderThickness}"/>
-  <Setter Property="Padding" Value="4,2"/>
-  <Setter Property="Template">
-    <ControlTemplate>
-      <ContentPresenter Name="PART_ContentPresenter"
-                        Background="{TemplateBinding Background}"
-                        BorderBrush="{TemplateBinding BorderBrush}"
-                        BorderThickness="{TemplateBinding BorderThickness}"
-                        ContentTemplate="{TemplateBinding ContentTemplate}"
-                        Content="{TemplateBinding Content}" 
-                        Padding="{TemplateBinding Padding}"/>
-    </ControlTemplate>
-  </Setter>
-</Style>
\ No newline at end of file
+<Styles xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+  <Design.PreviewWith>
+    <Grid RowDefinitions="Auto,Auto"
+          ColumnDefinitions="Auto,Auto"
+          HorizontalAlignment="Center">
+      <Border Grid.Column="0"
+              Grid.Row="1"
+              Background="{DynamicResource ThemeAccentBrush}"
+              Margin="5"
+              Padding="50"
+              ToolTip.Tip="Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.">
+        <TextBlock>Hover Here</TextBlock>
+      </Border>
+      <CheckBox Grid.Column="1"
+                Margin="5"
+                Grid.Row="0"
+                IsChecked="{Binding ElementName=Border, Path=(ToolTip.IsOpen)}"
+                Content="ToolTip Open" />
+      <Border Name="Border"
+              Grid.Column="1"
+              Grid.Row="1"
+              Background="{DynamicResource ThemeAccentBrush}"
+              Margin="5"
+              Padding="50"
+              ToolTip.Placement="Bottom">
+        <ToolTip.Tip>
+          <StackPanel>
+            <TextBlock Classes="h1">ToolTip</TextBlock>
+            <TextBlock Classes="h2">A control which pops up a hint when a control is hovered</TextBlock>
+          </StackPanel>
+        </ToolTip.Tip>
+        <TextBlock>ToolTip bottom placement</TextBlock>
+      </Border>
+    </Grid>
+  </Design.PreviewWith>
+
+  <Style Selector="ToolTip">
+    <Setter Property="Foreground" Value="{DynamicResource ToolTipForeground}" />
+    <Setter Property="Background" Value="{DynamicResource ToolTipBackground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ToolTipBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource ToolTipBorderThemeThickness}" />
+    <Setter Property="FontFamily" Value="{DynamicResource ContentControlThemeFontFamily}" />
+    <Setter Property="FontSize" Value="{DynamicResource ToolTipContentThemeFontSize}" />
+    <Setter Property="Padding" Value="{DynamicResource ToolTipBorderThemePadding}" />
+    <Setter Property="Transitions">
+      <Transitions>
+        <DoubleTransition Property="Opacity" Duration="0:0:0.15" />
+      </Transitions>
+    </Setter>
+    <Setter Property="Template">
+      <ControlTemplate>
+        <Border Name="PART_LayoutRoot"
+                BorderThickness="{TemplateBinding BorderThickness}"
+                Background="{TemplateBinding Background}"
+                BorderBrush="{TemplateBinding BorderBrush}"
+                Padding="{TemplateBinding Padding}"
+                CornerRadius="{DynamicResource OverlayCornerRadius}">
+          <ContentPresenter Name="PART_ContentPresenter"
+                            MaxWidth="320"
+                            Content="{TemplateBinding Content}"
+                            ContentTemplate="{TemplateBinding ContentTemplate}" />
+        </Border>
+      </ControlTemplate>
+    </Setter>
+  </Style>
+
+  <Style Selector="ToolTip > TextBlock">
+    <Setter Property="TextWrapping" Value="Wrap" />
+  </Style>
+
+  <Style Selector="ToolTip">
+    <Setter Property="Opacity" Value="0" />
+  </Style>
+
+  <Style Selector="ToolTip:open">
+    <Setter Property="Opacity" Value="1" />
+  </Style>
+</Styles>
diff --git a/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs b/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
index dc5b574db7..34b37e7635 100644
--- a/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ToolTipTests.cs
@@ -102,5 +102,76 @@ namespace Avalonia.Controls.UnitTests
                 Assert.True(ToolTip.GetIsOpen(target));
             }
         }
+
+        [Fact]
+        public void Open_Class_Should_Not_Initially_Be_Added()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                Assert.Empty(toolTip.Classes);
+            }
+        }
+
+        [Fact]
+        public void Setting_IsOpen_Should_Add_Open_Class()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                ToolTip.SetIsOpen(decorator, true);
+
+                Assert.Equal(new[] { ":open" }, toolTip.Classes);
+            }
+        }
+
+        [Fact]
+        public void Clearing_IsOpen_Should_Remove_Open_Class()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var toolTip = new ToolTip();
+                var window = new Window();
+
+                var decorator = new Decorator()
+                {
+                    [ToolTip.TipProperty] = toolTip
+                };
+
+                window.Content = decorator;
+
+                window.ApplyTemplate();
+                window.Presenter.ApplyTemplate();
+
+                ToolTip.SetIsOpen(decorator, true);
+                ToolTip.SetIsOpen(decorator, false);
+
+                Assert.Empty(toolTip.Classes);
+            }
+        }
     }
 }