whatsapp_web_groups/data/hr_efficiency_cron.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data noupdate="1">
        <record id="ir_cron_hr_efficiency_calculation" model="ir.cron">
            <field name="name">HR Efficiency: Calculate Efficiency (Weekly)</field>
            <field name="model_id" ref="model_hr_efficiency"/>
            <field name="state">code</field>
            <field name="code">model._cron_calculate_efficiency()</field>
            <field name="interval_number">1</field>
            <field name="interval_type">weeks</field>
            <field name="active" eval="True"/>
            <field name="priority">10</field>
            <field name="nextcall" eval="(DateTime.now() + timedelta(days=7)).strftime('%Y-%m-%d %H:%M:%S')"/>
        </record>
    </data>
</odoo>