SSRS: Scheduling a report to run at monthend

Is there an easy way to schedule a report to run on the last day of every month?
It is obvious and easy to run something on the 1st day of the month, each and every month.
But I can't get SSRS to accept 31 or 'Last' as a parameter so that I may create a "month end" schedule.
This doesn't seem like an obscure idea so there must be a quick-n-easy way to do this that I'm not seeing and cannot find in Books Online or my SSRS books.
Am I going to have to (yuck) write a script to do this?