diff --git a/lib/nntp/tiny/message.py b/lib/nntp/tiny/message.py
index 08dbb5a..f29b868 100644
--- a/lib/nntp/tiny/message.py
+++ b/lib/nntp/tiny/message.py
@@ -140,7 +140,7 @@ class Message(DatabaseTable):
             else:
                 value = self.header('Date')
 
-                if value is None:
+                if value is not None:
                     ret = search_dates(value)[0][1]
 
                     self._cache['created_on'] = str(ret)