diff --git a/kallithea/model/db.py b/kallithea/model/db.py
--- a/kallithea/model/db.py
+++ b/kallithea/model/db.py
@@ -2312,7 +2312,7 @@ class ChangesetStatus(Base, BaseDbModel)
     def __json__(self):
         return dict(
             status=self.status,
-            modified_at=self.modified_at,
+            modified_at=self.modified_at.replace(microsecond=0),
             reviewer=self.author.username,
             )