diff --git a/posts/firstpost.md b/posts/firstpost.md
index 01c8f54..c55696d 100644
--- a/posts/firstpost.md
+++ b/posts/firstpost.md
@@ -1,7 +1,7 @@
 ---
 title:  Introduction to Raspberry Pi
 description: This is my first post, it is an introduction to Raspberry Pi.
-date: 2021/10/15
+date: 2021-10-15
 tags:
   - first post
   - raspberry pi