diff --git a/src/App.tsx b/src/App.tsx
index f63a6c4..0496463 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -17,6 +17,7 @@
 import { CheckStatus } from "./pages/CheckStatus";
 import { AppServices } from "./global/AppServices";
 import { WebsocketProvider } from "./global/ws/WebsocketProvider";
+import { LocaleContext } from "./global/LocaleContext";
 
 import Debug from "debug";
 const debug = Debug("kristweb:app");
@@ -29,14 +30,16 @@
 
   return <Suspense fallback={<AppLoading />}>
     <Provider store={store}>
-      <WebsocketProvider>
-        <Router>
-          <CheckStatus />
+      <LocaleContext>
+        <WebsocketProvider>
+          <Router>
+            <CheckStatus />
 
-          {/* Services, etc. */}
-          <AppServices />
-        </Router>
-      </WebsocketProvider>
+            {/* Services, etc. */}
+            <AppServices />
+          </Router>
+        </WebsocketProvider>
+      </LocaleContext>
     </Provider>
   </Suspense>;
 }
diff --git a/src/__data__/languages.json b/src/__data__/languages.json
index 1e60b79..e8cc1a7 100644
--- a/src/__data__/languages.json
+++ b/src/__data__/languages.json
@@ -8,6 +8,7 @@
     "name": "German",
     "nativeName": "Deutsch",
     "country": "de",
+    "dayjsLocale": "de",
     "contributors": [
       {
         "name": "Lignum",
@@ -19,6 +20,7 @@
     "name": "French",
     "nativeName": "Français",
     "country": "fr",
+    "dayjsLocale": "fr",
     "contributors": [
       {
         "name": "Anavrins",
@@ -30,6 +32,7 @@
     "name": "Dutch",
     "nativeName": "Nederlands",
     "country": "nl",
+    "dayjsLocale": "nl",
     "contributors": [
       {
         "name": "HydroNitrogen",
@@ -41,6 +44,7 @@
     "name": "Vietnamese",
     "nativeName": "Tiếng Việt",
     "country": "vn",
+    "dayjsLocale": "vi",
     "contributors": [
       {
         "name": "Boom",
diff --git a/src/global/LocaleContext.tsx b/src/global/LocaleContext.tsx
new file mode 100644
index 0000000..2ad3dcf
--- /dev/null
+++ b/src/global/LocaleContext.tsx
@@ -0,0 +1,57 @@
+// Copyright (c) 2020-2021 Drew Lemmy
+// This file is part of KristWeb 2 under GPL-3.0.
+// Full details: https://github.com/tmpim/KristWeb2/blob/master/LICENSE.txt
+import { FC, useEffect } from "react";
+import { ConfigProvider } from "antd";
+import { Locale } from "antd/lib/locale-provider";
+import localeValues from "antd/lib/locale/default";
+
+import { useTranslation } from "react-i18next";
+import { getLanguages } from "@utils/i18n";
+
+import dayjs from "dayjs";
+
+import Debug from "debug";
+const debug = Debug("kristweb:locale-context");
+
+export const LocaleContext: FC = ({ children }): JSX.Element => {
+  const { t, i18n } = useTranslation();
+  const langCode = i18n.language;
+  const languages = getLanguages();
+
+  // Load the day.js locale if available
+  useEffect(() => {
+    if (!languages) return;
+    const lang = languages[langCode];
+
+    // See if the language has a dayjs locale set. If not, revert to `en`
+    const dayjsLocale = lang?.dayjsLocale;
+    if (!dayjsLocale) {
+      debug("language %s doesn't have a dayjs locale, reverting to `en`", langCode);
+      dayjs.locale("en");
+      return;
+    }
+
+    // Attempt to import the locale asynchronously. This will usually incur a
+    // network request, but it should be cached by the service worker.
+    debug("loading dayjs locale %s for language %s", dayjsLocale, langCode);
+    // Including only `.js` files here ensures that it doesn't attempt to load
+    // the TypeScript typings, which causes build warnings due to a missing
+    // loader for those files.
+    import(
+      /* webpackInclude: /\.js$/ */
+      /* webpackMode: "lazy" */
+      /* webpackChunkName: "locale-dayjs-[request]" */
+      `dayjs/locale/${dayjsLocale}`
+    )
+      .then(() => {
+        debug("got dayjs locale %s", dayjsLocale);
+        dayjs.locale(dayjsLocale);
+      })
+      .catch(console.error);
+  }, [langCode, languages]);
+
+  return <ConfigProvider>
+    {children}
+  </ConfigProvider>;
+};
diff --git a/src/service-worker.ts b/src/service-worker.ts
index 5f5610f..4aeb74b 100644
--- a/src/service-worker.ts
+++ b/src/service-worker.ts
@@ -24,7 +24,12 @@
 // Their URLs are injected into the manifest variable below.
 // This variable must be present somewhere in your service worker file,
 // even if you decide not to use precaching. See https://cra.link/PWA
-precacheAndRoute(self.__WB_MANIFEST);
+
+// Filter out all locale files from the precache. There's usually a few hundred
+// of these, so we definitely don't want to download them all on install!
+const filteredManifest = self.__WB_MANIFEST
+  .filter(u => !(typeof u === "string" ? u : u.url).includes("locale-"));
+precacheAndRoute(filteredManifest);
 
 // Cache the locale files (currently the only preloading step)
 registerRoute(
diff --git a/src/utils/i18n.ts b/src/utils/i18n.ts
index 7f48db2..530c774 100644
--- a/src/utils/i18n.ts
+++ b/src/utils/i18n.ts
@@ -21,6 +21,7 @@
   name: string;
   nativeName?: string;
   country?: string;
+  dayjsLocale?: string;
   contributors: Contributor[];
 }