Why design matters
Three watering days a week is plenty, if the system is right.
Colorado Springs Utilities limits sprinkler watering to three days a week, and from May 1 to October 15 sprinklers can't run between 10 a.m. and 6 p.m. Other Front Range providers have similar rules, and they can tighten in a drought year.
A landscape stays healthy under those rules when the system puts water down evenly and only where it's needed. That comes from design: matched heads, correct spacing, and lawn, beds and trees each on their own zone.