oca-technical/odoo-bringout-oca-account-closing-account_multicurrency_revaluation/account_multicurrency_revaluation/demo/currency_demo.xml

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <record model="res.currency.rate" id="currency_rate_gbp_01">
        <field eval="time.strftime('%Y-01-15')" name="name" />
        <field name="rate">2</field>
        <field name="currency_id" ref="base.GBP" />
        <field name="company_id" ref="res_company_reval" />
    </record>
    <record model="res.currency.rate" id="currency_rate_gbp_02">
        <field eval="time.strftime('%Y-02-15')" name="name" />
        <field name="rate">4</field>
        <field name="currency_id" ref="base.GBP" />
        <field name="company_id" ref="res_company_reval" />
    </record>
    <record model="res.currency.rate" id="currency_rate_gbp_03">
        <field eval="time.strftime('%Y-03-15')" name="name" />
        <field name="rate">2.5</field>
        <field name="currency_id" ref="base.GBP" />
        <field name="company_id" ref="res_company_reval" />
    </record>
</odoo>