diff --git a/panoramix/migrations/versions/18e88e1cc004_making_audit_nullable.py b/panoramix/migrations/versions/18e88e1cc004_making_audit_nullable.py
new file mode 100644
index 0000000000000..bd5f850cce7ce
--- /dev/null
+++ b/panoramix/migrations/versions/18e88e1cc004_making_audit_nullable.py
@@ -0,0 +1,100 @@
+"""making audit nullable
+
+Revision ID: 18e88e1cc004
+Revises: 430039611635
+Create Date: 2016-03-13 21:30:24.833107
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '18e88e1cc004'
+down_revision = '430039611635'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('clusters', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('clusters', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+
+    try:
+        op.drop_constraint(None, 'columns', type_='foreignkey')
+        op.drop_constraint(None, 'columns', type_='foreignkey')
+        op.drop_column('columns', 'created_on')
+        op.drop_column('columns', 'created_by_fk')
+        op.drop_column('columns', 'changed_on')
+        op.drop_column('columns', 'changed_by_fk')
+    except:
+        pass
+    op.alter_column('css_templates', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('css_templates', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('dashboards', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('dashboards', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.create_unique_constraint(None, 'dashboards', ['slug'])
+    op.alter_column('datasources', 'changed_by_fk',
+               existing_type=sa.INTEGER(),
+               nullable=True)
+    op.alter_column('datasources', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('datasources', 'created_by_fk',
+               existing_type=sa.INTEGER(),
+               nullable=True)
+    op.alter_column('datasources', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('dbs', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('dbs', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('slices', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('slices', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('sql_metrics', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('sql_metrics', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('table_columns', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('table_columns', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('tables', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('tables', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('url', 'changed_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    op.alter_column('url', 'created_on',
+               existing_type=sa.DATETIME(),
+               nullable=True)
+    ### end Alembic commands ###
+
+
+def downgrade():
+    pass
diff --git a/panoramix/models.py b/panoramix/models.py
index 69a66466fa60d..410d0c905416a 100644
--- a/panoramix/models.py
+++ b/panoramix/models.py
@@ -35,6 +35,10 @@
 
 
 class AuditMixinNullable(AuditMixin):
+    created_on = Column(DateTime, default=datetime.now, nullable=True)
+    changed_on = Column(
+        DateTime, default=datetime.now,
+        onupdate=datetime.now, nullable=True)
     @declared_attr
     def created_by_fk(cls):
         return Column(Integer, ForeignKey('ab_user.id'),