Invalidate defaultObjects if timezone changes

src/js/i18n.js

Index: src/js/i18n.js
diff --git a/src/js/i18n.js b/src/js/i18n.js
index b3a0f5b6ebd1783b8b884c462f207b82bcaf8cff..994c2328019f0fe5705ea0905479f4e17bd7ee73 100644
--- a/src/js/i18n.js
+++ b/src/js/i18n.js
@@ -1989,6 +1989,23 @@ var defaultObjects = {
   'dateformattime': UNDEFINED,
 };
 
+function clearDefaultObjects() {
+  defaultObjects['dateformatall'] = UNDEFINED;
+  defaultObjects['dateformatdate'] = UNDEFINED;
+  defaultObjects['dateformattime'] = UNDEFINED;
+}
+
+var date_cache_version = 0;
+
+function checkDateCacheCurrent() {
+  var new_date_cache_version = %DateCacheVersion();
+  if (new_date_cache_version == date_cache_version) {
+    return;
+  }
+  date_cache_version = new_date_cache_version;
+
+  clearDefaultObjects();
+}
 
 /**
  * Returns cached or newly created instance of a given service.
@@ -1997,6 +2014,7 @@ var defaultObjects = {
 function cachedOrNewService(service, locales, options, defaults) {
   var useOptions = (IS_UNDEFINED(defaults)) ? options : defaults;
   if (IS_UNDEFINED(locales) && IS_UNDEFINED(options)) {
+    checkDateCacheCurrent();
     if (IS_UNDEFINED(defaultObjects[service])) {
       defaultObjects[service] = new savedObjects[service](locales, useOptions);
     }