@Ian – thx for your reply. Not sure what happened to my post. … I Made an edit and “gone”. None the less, I have been thinking about a solution to what appears to be gap in the options in OS … What “I” really need is a weighted moving average of the calculated %watering since the last watering (I think), or at least the last several days … say 3 … This way, both the OWM and ETo or Zimmerman data come in to play – say a weighting of 60%(watering day = today), 30%(yesterday) and 10%(day before). … Or, since I have an OS3 I might try implementing something through the second sensor switch and a sonoff relay – effectively a shut-off if there has been enough rain in the last n days (similar weighting as above) … but for now I will adjust manually, but this is like having a dog and barking yourself.