Use Mixins for global functions.

src/main.js

@@ -12,7 +12,33 @@ import App from './App.vue'
 
 import './registerServiceWorker'
 
+const mixin = {
+    methods: {
+        timeFormat: function (duration) {
+
+            var pad = function (num, size) {
+                return ("000" + num).slice(size * -1);
+            };
+
+            var time = parseFloat(duration).toFixed(3),
+                hours = Math.floor(time / 60 / 60),
+                minutes = Math.floor(time / 60) % 60,
+                seconds = Math.floor(time - minutes * 60);
+
+            var str = "";
+
+            if (hours > 0) str += pad(hours, 2) + ":";
+
+            str += pad(minutes, 2) + ":" + pad(seconds, 2);
+
+            return str;
+
+        }
+    }
+}
+
 const app = createApp(App)
 app.use(router)
+app.mixin(mixin)
 app.component('font-awesome-icon', FontAwesomeIcon)
 app.mount('#app')