diff --git a/rhodecode/model/db.py b/rhodecode/model/db.py
--- a/rhodecode/model/db.py
+++ b/rhodecode/model/db.py
@@ -1427,7 +1427,8 @@ class ChangesetComment(Base, BaseModel):
     f_path = Column('f_path', Unicode(1000), nullable=True)
     user_id = Column('user_id', Integer(), ForeignKey('users.user_id'), nullable=False)
     text = Column('text', Unicode(25000), nullable=False)
-    modified_at = Column('modified_at', DateTime(), nullable=False, default=datetime.datetime.now)
+    created_on = Column('created_on', DateTime(timezone=False), nullable=False, default=datetime.datetime.now)
+    modified_at = Column('modified_at', DateTime(timezone=False), nullable=False, default=datetime.datetime.now)
 
     author = relationship('User', lazy='joined')
     repo = relationship('Repository')