Hello, @jeasalva. I'm very eager to share some workarounds and information about invoice service dates in QuickBooks Online.

You have the option to enter different service dates while using the same item on your invoice.

Please see this sample screenshot for reference:

In addition, I've got this helpful resource to know more about customization: How to customize invoices, estimates, and sales receipts.

Get back to me here if you have further questions about managing your invoice. I'd be more than happy to answer it for you. Have a nice day.