diff --git a/_includes/default.liquid b/_includes/default.liquid
index f3c3f60..1ddd390 100644
--- a/_includes/default.liquid
+++ b/_includes/default.liquid
@@ -24,7 +24,7 @@
         <a href="https://tilde.linuxposting.xyz/ring.py?next&amp;tilde.linuxposting.xyz/~jhalfsharp">→</a>
         </span>
         <br>
-        <span class="last-modified">Page last modified on {{ page.date }}</span>
+        <span class="last-modified">Page last modified on {{ page.date | rfcdate }}</span>
       </footer> 
     </div>
     {{ scripts }}
diff --git a/eleventy.config.mjs b/eleventy.config.mjs
index 3badd04..d04d165 100644
--- a/eleventy.config.mjs
+++ b/eleventy.config.mjs
@@ -10,6 +10,10 @@ export default function (eleventyConfig) {
     eleventyConfig.addPassthroughCopy("assets/images");
     eleventyConfig.addPassthroughCopy("assets/fonts");
 
+    eleventyConfig.addFilter("rfcdate", function (date) {
+        return `${date.getUTCFullYear()}-${(date.getUTCMonth() + 1).toString().padStart(2, "0")}-${date.getUTCDate().toString().padStart(2, "0")} ${date.getUTCHours().toString().padStart(2, "0")}:${date.getUTCMinutes().toString().padStart(2, "0")}:${date.getUTCSeconds().toString().padStart(2, "0")}`
+    })
+
     // Creates the extension for use
     eleventyConfig.addExtension("scss", {
         outputFileExtension: "css", // optional, default: "html"