Unless you are one of those people who thinks their lawn should look like a golf course, you don't need to water more than once every two weeks for 5-10 minutes for each zone at most. Most of the year, it can be turned off - no need to water in spring until late June.

July, August, September are the major sprinkler months.

Sprinkler usage will up your water bill quite a bit.

More detailed watering instructions would be dependent on your actual landscape and plants.

Also figure out how to run it manually, so you can make a map of what area each zone actually covers. Water really early in the morning or late at night. In wetter months, late at night is a bad idea, but in the Dallas summer it's fine.

Any summer watering after 11:00am or so, you're just wasting money to evaporation.

If you are a golf course lawn person, expect to pay. If not then start with what I said and then adjust if it's looking a bit dry.

Also check if you have a low-flow foundation watering zone. that one is needed probably once a week in the summer, depending on if you've had foundation repairs or not.