How to use current date in a domain in XML

Hello everyone.
I’m trying to create a domain that compares a field with the current date. This is what I have tested so far in my xml :

        <record model="ir.action.act_window.domain" id="act_invoicing_element_not_invoiced">
            <field name="name">Not Invoiced</field>
            <field name="sequence" eval="1"/>
            <field name="domain" eval="[('mission_order', '!=', None), ('invoiced', '=', False), ('date', '<', Date())]" pyson="1"/>
            <field name="count" eval="True"/>
            <field name="act_window" ref="act_invoicing_element"/>
        </record>

But tryton does not like the Date() part and displays an error when I try to update my module :
Exception: Error in Tag record with id transport.act_invoicing_element_not_invoiced.
I have seen on this topic that you can use DateTime(), but does anybody know if Date() also works ? How should I write my domain ?

Date is a valid PYSON. I suspect that the error is somewhere else but it is not possible as you did not provide the full traceback.

Indeed the problem was not with Date(), but with the ‘<’ character, that should be escaped, as you explained on this page Problem with pyson, domain, and xml (google.com)
The correct syntax should be :

<field name="domain" eval="[('mission_order', '!=', None), ('invoiced', '=', False), ('date', '&lt;', Date())]" pyson="1"/>

With this syntax I don’t have an error when I try to update my module.

Thanks @ced