Fix the sitemap indexes

astro/src/pages/sitemap/index.xml.ts

@@ -1,3 +1,4 @@
+import { getAllBlogs } from "@/content/blogs/blogs";
 import { getSettings } from "@/content/settings/settings";
 import type { APIRoute } from "astro";
 import minifyXML from "minify-xml";
@@ -13,9 +14,25 @@ export const GET = (async () => {
     ];
 
     if (settings.blog.enabled) {
+        const blogLastModifieds = [
+            settings.blog.lastModified,
+            settings.sitemap.lastModified,
+            settings.website.lastModified
+        ];
+
+        let blogs = await getAllBlogs(settings);
+
+        blogs.forEach((blog) => {
+            blogLastModifieds.push(blog.lastModified);
+        });
+
+        const lastModifiedBlogs = blogLastModifieds.sort((a: Date, b: Date) => {
+            return b.getTime() - a.getTime();
+        });
+
         sitemapIndex.push({
             url: "/sitemap/blogs.xml",
-            lastModified: new Date()
+            lastModified: lastModifiedBlogs[0]
         });
     };
     if (settings.project.enabled) {