It also calculates absorption rate of soil and nose to water multiple times a day I start my day at 4 a.m. it will start one zone for 10 minutes then wait 30 minutes and then do it again for 10 minutes sometimes based on when the sun comes up it will reschedule and do it right before the sun rises it tries to find the most optimal time for water moisture to be absorbed but there are many factors as to why it doesn't in these ways although I will say without a Sprite it's only guessing what the moisture level of the water is based on what it has already done make sure you select the correct soil