Calculate date of retirement

1

I want to calculate date of retirement such that :slight_smile:
date of retirement = date of birth+60 years
this is script
frappe.ui.form.on(‘Employee’, {
‘date_of_retirement’: frm => {
frm.doc.date_of_birth && frm.set_value(‘date_of_retirement’, frappe.datetime.add_years(frm.doc.date_of_birth, 60));
}
}) ;

It does not work could you please support me?