Great content and very useful but I take exception with a couple pieces of the examples from your text: "Based on the setup of period between delivery and invoice, which is 5 days, the date will be January 6, 2013 (PO date + 5 days)." The first sentence should read PO line receipt date, not PO date. "Based on the setup of invoicing period, which is 7 days, the date will be January 13, 2013 (PO date + 5 days + 7 days)." The second line has a practical error: regardless of when the invoice is received, the conventional business practice is to begin the terms (aging) from the delivery date and use that date for the invoice date even if the invoice is not received until 7 days later. I would set this factor to zero days.