If those payables (purchase invoices) are not paid yet, then the easiest way to correct them would be to Invalidate them. Open a payable (purchase invoice) and then from the Record menu select - Invalidate. Then create a new payable with the correct date.

If a payable is paid, create a credit memo (credit note) against the payable with the same date as the payable. Then create a new payable with the correct date. The original payable will now have a negative balance, so you will need to create a new payment in which you select both payables (the original and the new one). This will clear the balance.

HansaWorld Support Team