Thanks -- that's a start.  But the sort/filter by invoice date won't get me quite where I need to be.

This report will give me all invoices sorted or filtered by the date of the invoice.

I need a list of customers who have no invoices after a certain date -- example: a list of all customers whose last invoice is dated before January 1, 2019 (i.e., who have had no transactions since then).

Filtering this transaction report by date of invoice will show all invoices dated on or before a certain date -- but it won't tell me whether the customer has had any transactions since then.

Any way to get that information?