Water between the hours of 9pm and 6am to avoid evaporation during daylight hours. The NFBWA’s Larry the Talking Sprinkler says you only need to water your lawn twice a week. Cinco MUD 8 recommends watering for 8 minutes for each zone and replace any broken sprinkler heads. See Cinco MUD 8’s site for rebate info.
See http://www.cincomud8.com for rebates on WaterSense Labeled controllers or sprinkler heads.