diff --git a/db.py b/db.py
index 3e0bbfa..665db2e 100644
--- a/db.py
+++ b/db.py
@@ -177,7 +177,11 @@ class VkPost(db.Model):
             "selected_users": self.selected_users,
             "full_name": self.full_name,
             "post_id": self.post_id,
-            "publish_at": self.publish_at,
+            "publish_at": (
+                self.publish_at.strftime("%Y-%m-%d %H:%M:%S")
+                if self.publish_at
+                else None
+            ),
             "created_at": self.created_at.strftime("%Y-%m-%d %H:%M:%S"),
             "updated_at": self.updated_at.strftime("%Y-%m-%d %H:%M:%S"),
         }