Currently, I just see the Schedule working hours and timezone with developer mode.
So, how to make the Schedule visible without developer mode?
You need to inherit form view and replace group section. It will be easy.
Something like:
<record id="view_employee_form" model="ir.ui.view">
<field name="name">hr.employee.form</field>
<field name="model">hr.employee</field>
<field name="inherit_id" ref="hr.view_employee_form"/>
<field name="arch" type="xml">
<xpath expr="//notebook/page/div/div/group[4]" position="replace">
<group string="Schedule">
<field name="resource_calendar_id" required="1"/>
<field name="tz"/>
</group>
</xpath>
</field>
</record>