Use the decorated-tree icon for the month of December.

Evergreen/Assets.xcassets/AppIcon-Normal.appiconset/Contents.json

@@ -0,0 +1,68 @@
+{
+  "images" : [
+    {
+      "size" : "16x16",
+      "idiom" : "mac",
+      "filename" : "icon_16x16.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "16x16",
+      "idiom" : "mac",
+      "filename" : "icon_16x16@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "32x32",
+      "idiom" : "mac",
+      "filename" : "icon_32x32.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "32x32",
+      "idiom" : "mac",
+      "filename" : "icon_32x32@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "128x128",
+      "idiom" : "mac",
+      "filename" : "icon_128x128.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "128x128",
+      "idiom" : "mac",
+      "filename" : "icon_128x128@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "256x256",
+      "idiom" : "mac",
+      "filename" : "icon_256x256.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "256x256",
+      "idiom" : "mac",
+      "filename" : "icon_256x256@2x.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "512x512",
+      "idiom" : "mac",
+      "filename" : "icon_512x512.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "512x512",
+      "idiom" : "mac",
+      "filename" : "icon_512x512@2x.png",
+      "scale" : "2x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

Evergreen/Info.plist

@@ -17,9 +17,9 @@
 	<key>CFBundlePackageType</key>
 	<string>APPL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0d22</string>
+	<string>1.0d23</string>
 	<key>CFBundleVersion</key>
-	<string>514</string>
+	<string>515</string>
 	<key>LSMinimumSystemVersion</key>
 	<string>$(MACOSX_DEPLOYMENT_TARGET)</string>
 	<key>NSHumanReadableCopyright</key>