Go to districtgov.org and click on the "Water wise" box. It will tell you how long to water with rotors & sprays and how to adjust for different times of the year.

When we moved in 7 years ago, our system was set up to start at 2 or 2:30AM and our day to water was according to the house number. After reading some articles I changed it to 4AM, now have it start at 3:30AM Thrs & Sunday.