diff --git a/contrib/stack/topsStack/fetchOrbit.py b/contrib/stack/topsStack/fetchOrbit.py
index 6bfb3fdc4b6d63cdeac9f882c3b33174f3f81cff..ac67b2e5ac9f68908695946affbf3c5fd069343d 100644
--- a/contrib/stack/topsStack/fetchOrbit.py
+++ b/contrib/stack/topsStack/fetchOrbit.py
@@ -170,7 +170,7 @@ if __name__ == '__main__':
             entries = json.loads(r.text, object_hook=lambda x: SimpleNamespace(**x)).value
 
             for entry in entries:
-                entry_datefmt = "%Y-%m-%dT%H:%M:%S.000Z"
+                entry_datefmt = "%Y-%m-%dT%H:%M:%S.000000Z"
                 tbef = datetime.datetime.strptime(entry.ContentDate.Start, entry_datefmt)
                 taft = datetime.datetime.strptime(entry.ContentDate.End, entry_datefmt)
                 if (tbef <= fileTSStart) and (taft >= fileTS):