diff --git a/crawler/data_access.py b/crawler/data_access.py
index 0bad232..e894f9b 100644
--- a/crawler/data_access.py
+++ b/crawler/data_access.py
@@ -220,7 +220,8 @@ class Listing:
         
         with open(self.path_last_seen_listing(), 'r') as f:
             datetime_str = json.load(f)
-            return datetime.fromisoformat(datetime_str)
+            dt = datetime.datetime.fromisoformat(datetime_str)
+            return (datetime.datetime.now() - dt).days
 
     @property
     def serviceCharge(self) -> float: