diff --git a/_config.yml b/_config.yml
index 3dd22af4..7b11a5ff 100644
--- a/_config.yml
+++ b/_config.yml
@@ -42,7 +42,7 @@ staticman:
     date:
       type: "date"
       options:
-        format: "iso8601" # "iso8601" (default), "timestamp"
+        format: "timestamp-seconds" # "iso8601" (default), "timestamp-seconds", "timestamp-milliseconds"
 atom_feed:
   path                   : # blank (default) uses feed.xml