base_user_role/data/ir_cron.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2016 ABF OSIELL <http://osiell.com>
     License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl). -->
<openerp>
    <data noupdate="1">

        <record model="ir.cron" id="cron_update_users">
            <field name='name'>Update user roles</field>
            <field name='interval_number'>3</field>
            <field name='interval_type'>hours</field>
            <field name="numbercall">-1</field>
            <field name="active">True</field>
            <field name="doall" eval="False" />
            <field name="model">res.users.role</field>
            <field name="function">cron_update_users</field>
            <field name="args">()</field>
        </record>

    </data>
</openerp>