Hi,
To create a custom module in Odoo 17 for notifying employees about passport and ID expiry dates, you can follow these steps:
Inherit hr.employee to add necessary fields and functions:
class HrEmployee(models.Model):    _inherit = 'hr.employee'
    passport_expiry_date = fields.Date(string='Passport Expiry Date')
    id_expiry_date = fields.Date(string='ID Expiry Date')
    @api.model
    def notify_passport_expiry(self):
        today = fields.Date.today()
        one_month_later = today + timedelta(days=30)
        employees_to_notify = self.search([
            ('passport_expiry_date', '=', one_month_later)
        ])
        for employee in employees_to_notify:
            template = self.env.ref('your_module.email_template_passport_expiry')
            template.send_mail(employee.id, force_send=True)
Scheduled action corresponding to this:
    <record id="ir_cron_employee_email" model="ir.cron">
        <field name="name">Passport Expiry</field>
        <field name="model_id" ref="model_hr_employee"/>
        <field name="state">code</field>
<field name="code">model.notify_passport_expiry()</field>
<field name="interval_number">1</field>
<field name="interval_type">days</field>
        <field name="numbercall">-1</field>
    </record>
Also create an email template:
<record id="email_template_passport_expiry" model="mail.template">        <field name="name">Passport Expiry Notification</field>
        <field name="model_id" ref="hr.model_hr_employee"/>
        <field name="email_from">${user.email|safe}</field>
        <field name="subject">Passport Expiry Notification</field>
        <field name="body_html">
            <![CDATA[
            <p>Hello ${object.name},</p>
            <p>Your passport is expiring on ${object.passport_expiry_date}. Please renew it soon.</p>
            ]]>
        </field>
        <field name="auto_delete" eval="True"/>
    </record>
Hope it helps