I love in the high desert with some of the most expressive water in the world. If I had the same problem and my back yard flooded over night, that would be at least a $200 mistake, assuming I didn’t get a fine on top of the water wasted. I’m very sensitive to this stuff as a result.
Now that you have it working, think about all the error cases. What happens if oh reboots while the system is on? (Hint, all your timers will go away). What happens if oh is off during the time that a zone is supposed to turn on or off? Is there any feedback to let you know whethera barber is open or closed?
Have a look at Design Pattern: Cascading Timers for a way to deal with most of these edge cases.