Can we update budget date on PO which is in closed status and is received and invoiced with payment?

Can we update the budget date on the PO which is in closed status and is received and invoiced with payment is been made?

Can we trigger the budget date to automatically update when a CO is processed to the current date?

How can we correct where the budget date was not automatically updated and later receipts and invoices are processed against the older budget date?

How can we update the budget date when changes are made if invoices & receipts have already been posted a invoices have already paid.?