If I am understanding everything I am reading, there is a known display issue that support is working on. See http://community.rachio.com/t/device-offline-not-watering/2115/9.
For me, the web app and the app on my iPhone rarely match on when it’s going to water next. And even if they did, it’s still only an estimate as I believe it re-evaluates and comes up with the actual schedule about one hour before the watering schedule actually begins.
Pro: My watering for my lawn zones seem to be occurring pretty much when needed, and it’s watering more appropriately than my previous system (and that system I had to ignore the next scheduled watering totally as it was NEVER any where close to correct)
Con: There are variations between the displays depending on where you access it from. And reporting of actual minutes watered is not consistent across different displays of the information at all. (While important and I hope they get this fixed soon, it does seem to be doing a good job of getting the watering done on Flex schedules much better than my old system.)