Build for compatibility with iOS 9.3 (last supported on iPad >=2)

had to change browserslist, set up babel, and polyfill 'Intl'

babel.config.json

@@ -0,0 +1,11 @@
+{
+  "plugins": ["@babel/plugin-transform-runtime"],
+  "presets": [
+    [
+      "@babel/preset-env",
+      {
+        "useBuiltIns": "usage"
+      }
+    ]
+  ]
+}

package.json

@@ -1,12 +1,15 @@
 {
   "browserslist": [
-    "last 1 Chrome versions",
-    "last 1 Firefox versions"
+    "defaults",
+    "ios 9.3"
   ],
   "scripts": {
     "start": "parcel src/index.html"
   },
   "devDependencies": {
+    "@babel/core": "^7.8.7",
+    "@babel/plugin-transform-runtime": "^7.8.3",
+    "@babel/preset-env": "^7.8.7",
     "@vue/component-compiler-utils": "^3.0.0",
     "sass": "^1.23.1",
     "typescript": "^3.6.4",
@@ -17,7 +20,9 @@
     "@fullcalendar/google-calendar": "^4.3.0",
     "@fullcalendar/timegrid": "^4.3.0",
     "@fullcalendar/vue": "^4.3.1",
+    "core-js": "^3.6.4",
     "equicolor": "^1.1.0",
+    "intl": "^1.2.5",
     "vue": "^2.6.10",
     "vue-hot-reload-api": "^2.3.4",
     "vue-property-decorator": "^8.3.0"

src/index.ts

@@ -1,3 +1,14 @@
+import 'core-js/modules/es.object.entries';
+
+// TODO: could probably be a dynamic import
+import intl from 'intl';
+import 'intl/locale-data/jsonp/en.js';
+
+if (!window.Intl) {
+  // No `Intl`, so use and load the polyfill.
+  window.Intl = intl;
+}
+
 import Vue from 'vue';
 
 import App from './App';