Payables Open Interface query

Hi all,

Have a query regarding the payables open interface.

If for instance, on the last day of the month, we close the AP period for say Jul-12, at 4pm. We have an interface that runs at 7pm which brings in a file into an external interface, before transferring the data to the payables open interface tables.
The file only contains a few fields. So the external table populates some additional information. One of them being the accounting_date field.

Now. When the import programs are run, the accounting_date on the payables open invoice lines table is populated with the accounting date '31-Jul-12' (since we are using Jul-12 as the example).