An Invoice was posted on the second day of our new year that should have been dated the last day of the prior year. It has since been paid. How do I adjust this to show the correct year?

There are two issues here: the G/L transactions and the A/P history.

At this point, I would adjust the General ledger by posting a manual set of adjustments there.

If the A/P history matters, you can edit that vendor's history. (You may need to enable that option in the Compnay Profile.)

Thanks Ralph, That's what I figured. A/P history isn't a big issue.