Use hourglass image rather than emoji

MenubarCountdown/AppDelegate.swift

@@ -179,14 +179,22 @@ class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCenterDele
         else {
             timeString = NSString(format: "%02d:%02d", hours, minutes) as String
         }
+        statusItem.button?.image = nil
         statusItem.button?.title = timeString
     }
 
     /**
      Change the status item to an hourglass icon
      */
     func showStatusItemIcon() {
-        statusItem.button?.title = "⌛️"
+        statusItem.button?.title = ""
+        if let image = NSImage(named: "HourglassIcon") {
+            image.isTemplate = true
+            statusItem.button?.image = image
+        }
+        else {
+            Log.error("unable to load HourglassIcon")
+        }
     }
 
     func startBlinking() {

MenubarCountdown/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

MenubarCountdown/Assets.xcassets/HourglassIcon.imageset/Contents.json

@@ -0,0 +1,21 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "filename" : "HourglassIconBlack.png",
+      "scale" : "1x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "universal",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}