diff --git a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
index 640bdf9cab..0a8c6868d3 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
@@ -193,7 +193,7 @@ export async function generateBlogPosts(
 
     // Prefer user-defined date.
     if (frontMatter.date) {
-      date = frontMatter.date;
+      date = new Date(frontMatter.date);
     }
 
     // Use file create time for blog.