There was a thread a few days ago about scheduling payments:
https://bitcointalk.org/index.php?topic=5140716.0Same basic theory applies here.
Also if you have any programming skills, it would be even easier. I threw together a php script after thinking about that topic that does it.
You need PHP & cron (or any scheduler) and that's it. It's unsecured and buggy but if I can do it, anyone with any real php skills can probably do something that does not suck.
-Dave