The sales order date set by the supplier
invoic_Examples
<documentReference documentType="SupplierOrder" id="24123456" date="2015-10-01" lineNo="1"> invoic_XPATH
/b24Message/invoice/item/documentReference[@documentType="SupplierOrder"]/@date
invoic_Required
No
invoic_Type
Date/Time
invoic_Sort
18200