Question
I see that Toro is not on your list of familiar appliances, so I hope it's OK to ask anyway.

Yesterday my automatic watering system (Toro TMC-212) turned itself on at an unscheduled time. It is set to run one program (A) 3 times a week. I checked that the correct day and time were showing, as well as station times and went through all other the settings to ensure they were not likely to be causing the problem. The remaining programs B and C are fully switched off.

This morning it again started at an unscheduled time -- and judging from the soil, it may well have been on during the night too.

I have now switched it from RUN to OFF -- this took a moment to register: although the display LED instantly showed OFF, it took a minute or so for the sprinklers to stop.

It seems like the electronic equivalent of a rush of blood to the head: a circuit, or programmer/controller malfunction? Any tips gratefully received, many thanks for your time and help.

Answer
Hello
First I would double check to make sure that you do not have multiple start times or programs. Then look in the manual for directions on how to reset the controller.  The activity that you are describing is something we see when the controller has suffered damage to the processor from a power surge.