The obvious inference here is that it changed to 4am tomorrow, but that is implied, not explicit. Adding the word 'tomorrow' or '31 August' would have made it more clear. This is a polish kind of fix, not a showstopper.
The fact that delaying the watering for a day brought the moisture balance far past zero is a separate issue. Not sure whether the forecast at 4:30am indicated it was going to overshoot zero by half or not.
So much fun. My yard looks amazing! So fluffy and green! I routinely brag about my yard on Facebook now. Makes me think, does the Rachio Facebook page allow users to upload their brag photos? If not, that should be a thing.