contract/contract_sale_generation/data/contract_cron.xml

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

    <record model="ir.cron" id="account_analytic_cron_for_sale">
        <field name="name">Generate Recurring sales from Contracts</field>
        <field name="interval_number">1</field>
        <field name="interval_type">days</field>
        <field name="numbercall">-1</field>
        <field name="model" eval="'account.analytic.account'"/>
        <field name="function" eval="'cron_recurring_create_sale'"/>
        <field name="args" eval="'()'"/>
    </record>

</odoo>