When I create a custom report, I try to edit the date range and if I am offered any options at all, it is constrained to the date range I selected when I ran it the first time, IF I created it as a recurring report. It would be immensely helpful to create a custom report, and be able to change the date range as needed. I have seen suggestions to globally change the date range, and that is great, too. Either way, creating these reports one at a time is not efficient.