Jim,
That's great. My guess was right, but I wanted to put it out there because I feel like it's great content for the forum (I did a search, there weren't any posts on this topic).
This is just another example of why what you're offering is a such a great solution.
Now that I'm such an avid user, I've been watching my neighbors and the town's irrigation systems. My neighbor's irrigation has been going on while mine hasn't. He doesn't even have a sensor, he has to manage rain cycles the old fashioned way, turning on and off his clock. Then of course he's turning his clock back on too soon. My bet is that when turns his clock back on he's running a normal cycle, when he only needs to run at a percentage. So he's watering when he shouldn't and watering too much. I also noticed the same issues with the town. Wasting water is not cool.
Everyone should be using your Program.