The answer to 'sprinkler system schedule' is that the optimal sprinkler system schedule will depend on your climate, lawn size, soil type, and other factors. As a general guideline, most lawns need about 1-2 inches of water per week during the growing season, either from rainfall or irrigation. This is typically achieved by running your sprinklers 2-3 times per week for 20-30 minutes each time.
The best time to water is typically early morning or late evening to minimize evaporation. Adjust your schedule based on weather conditions - water more during hot, dry spells and less during cooler, wetter periods. It's also important to avoid watering during the heat of the day, as this can lead to excessive evaporation and water waste.