Hi there, Douglas. I’ve noticed that you posted a similar concern to this forum about customizing invoices in QuickBooks Online. 

In that manner, my colleague has already responded to the thread you originally posted with the information you need. If you have not yet been notified of her response, you can go to this link to be routed accordingly: https://quickbooks.intuit.com/learn-support/en-us/reports-and-accounting/re-how-do-you-add-a-month-v.... 

Feel free to reach out to the Community whenever you have any questions or concerns about QuickBooks. I am here to assist you in any way possible.