Posting sales order invoices on the same date of the packing slip

We run at the end of the day a batch job to invoice all sales orders shipped during the day.

However it is important to set the “invoice date”/”posting date” to be the same date as the date of the packing slip (–> date of physical delivery).

This become an issue when our scheduled batch jobs runs after midnight.

Is there a way to make this batch job use the packing slip date instead of the “contemporary” date of when the batch job ran?