muk_web/muk_web_utils/data/autovacuum.xml

<?xml version="1.0" encoding="UTF-8"?>

<!--     
	Copyright (C) 2017 MuK IT GmbH
	
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>. 
-->

<odoo noupdate="1">

	<record id="autovacuum_temporary_attachments" model="muk_autovacuum.rules">
        <field name="name">Delete temporary Attachments</field>
        <field name="model" ref="base.model_ir_attachment"/>
        <field name="active" eval="True" />
        <field name="state">domain</field>
        <field name="domain">[('temporary','=',True), ('create_date', '&lt;=', (datetime.datetime.utcnow() - datetime.timedelta(hours=24)).strftime('%Y-%m-%d %H:%M:%S'))]</field>
        <field name="protect_starred" eval="False" />
    </record>

</odoo>