Add date filters

.eleventy.js

@@ -11,6 +11,25 @@ module.exports = function (eleventyConfig) {
     'node_modules/simpledotcss/simple.css': 'css/simple.css',
   });
 
+  eleventyConfig.addFilter("makeRfc822Date", function (value) {
+    return new Date(value).toUTCString();
+  });
+  eleventyConfig.addFilter("formatDatetimeForHumans", function (value) {
+    const dt = new Date(value);
+    const formattedDt = new Intl.DateTimeFormat("en", {
+      dateStyle: "medium",
+      timeStyle: "medium",
+    }).format(dt);
+    return formattedDt;
+  });
+  eleventyConfig.addFilter("formatDateForHumans", function (value) {
+    const dt = new Date(value);
+    const formattedDt = new Intl.DateTimeFormat("en", {
+      dateStyle: "medium",
+    }).format(dt);
+    return formattedDt;
+  });
+
   const markdownLibrary = markdownIt()
     .use(markdownItAnchor, { slugify })
     .use(