diff --git a/src/routes/sitemap.xml/+server.ts b/src/routes/sitemap.xml/+server.ts
index 91c928e..1a166ad 100644
--- a/src/routes/sitemap.xml/+server.ts
+++ b/src/routes/sitemap.xml/+server.ts
@@ -1,5 +1,6 @@
 import { json } from '@sveltejs/kit';
 import { browseAllPost } from "$lib/content/contentApi";
+import dayjs from 'dayjs';
 
 export async function GET() {
 
@@ -17,7 +18,7 @@ export async function GET() {
         allPosts.map((_post) => {
             xml += '<url>'
             xml += `<loc>${_post.url}</loc>`
-            xml += `<lastmod>${_post.date_updated}</lastmod>`
+            xml += `<lastmod>${dayjs(_post.date_updated).format('YYYY-MM-DDTHH:mm:ss[+07:00]')}</lastmod>`
             xml += `<changefreq>always</changefreq>`
             xml += `<priority>0.5</priority>`
             xml += '</url>'