diff --git a/migrations/006_date_posted.sql b/migrations/006_date_posted.sql
new file mode 100644
index 0000000..e55e8a6
--- /dev/null
+++ b/migrations/006_date_posted.sql
@@ -0,0 +1,6 @@
+-- 006_date_posted.sql
+-- Add date_posted column for shadow listing detection (stale/shadow score feature).
+-- New DBs already have this column from the CREATE TABLE statement in db.py;
+-- this migration adds it to existing user DBs.
+
+ALTER TABLE jobs ADD COLUMN date_posted TEXT;