Great to hear, daveamy! You can set up Net 15 as the terms of your invoice when you create it. You can even set up custom terms by clicking Add New from the Terms drop-down menu on the invoice creation screen, then entering the necessary information.

These terms are based on the Invoice date. I can see how having the option to change this based on shipping date would be helpful. You can submit feedback about this by clicking the Gear icon > Feedback.