prevent more hydration mismatches

components/Footer/Footer.tsx

@@ -93,7 +93,7 @@ const Footer = ({ ...rest }: FooterProps) => (
         <NextLink href="/previously/" prefetch={false} passHref={true}>
           <Link title="Previously on...">2001</Link>
         </NextLink>{" "}
-        – {new Date().getFullYear()}.
+        – {new Date(process.env.NEXT_PUBLIC_RELEASE_DATE).getUTCFullYear()}.
       </div>
 
       <div>

lib/config/constants.ts

@@ -2,7 +2,7 @@
 export const NOTES_DIR = "./notes";
 
 // normalize the timestamp saved when building/deploying (see next.config.js) and fall back to right now:
-export const RELEASE_DATE = new Date(process.env.RELEASE_DATE ?? Date.now()).toISOString();
+export const RELEASE_DATE = new Date(process.env.NEXT_PUBLIC_RELEASE_DATE ?? Date.now()).toISOString();
 
 // detect current backend environment
 export const IS_PROD = process.env.NEXT_PUBLIC_VERCEL_ENV === "production";

lib/helpers/parse-notes.ts

@@ -9,6 +9,7 @@ import { compiler } from "markdown-to-jsx";
 import removeMarkdown from "remove-markdown";
 import sanitizeHtml from "sanitize-html";
 import readingTime from "reading-time";
+import { formatDateISO } from "./format-date";
 import { baseUrl } from "../config";
 import { NOTES_DIR } from "../config/constants";
 
@@ -56,7 +57,7 @@ export const getNoteData = (slug: string): Omit<NoteType, "source"> & { content:
       htmlTitle,
       slug,
       permalink: urlJoin(baseUrl, "notes", slug, "/"),
-      date: new Date(data.date).toISOString(), // validate/normalize the date string provided from front matter
+      date: formatDateISO(data.date), // validate/normalize the date string provided from front matter
       readingMins: Math.ceil(readingTime(content).minutes),
     },
     content,

next.config.js

@@ -24,7 +24,7 @@ module.exports = (phase, { defaultConfig }) => {
     productionBrowserSourceMaps: true,
     env: {
       // freeze build timestamp for when serverless pages need a "last updated" date:
-      RELEASE_DATE: new Date().toISOString(),
+      NEXT_PUBLIC_RELEASE_DATE: new Date().toISOString(),
       // check if we're running locally via `next dev`:
       IS_DEV_SERVER: phase === PHASE_DEVELOPMENT_SERVER,
     },