letsencrypt/data/ir_cron.xml
<?xml version="1.0" encoding="UTF-8"?>
<openerp>
<data noupdate="1">
<record id="cronjob" model="ir.cron">
<field name="name">Update letsencrypt certificates</field>
<field name="interval_type">weeks</field>
<field name="interval_number">11</field>
<field name="numbercall">-1</field>
<field name="model">letsencrypt</field>
<field name="function">cron</field>
<field name="nextcall">2016-01-01</field>
</record>
</data>
</openerp>