Recommended watering times can vary greatly depending on many different factors. Temperature and precipitation are obviously the elements most likely to affect the time needed to keep your lawn green, but its also important to keep in mind things like the amount of shade an area gets throughout the day, the grade of slope, what type of sprinkler head is watering the area, and what type/size of nozzle is being used.
Setting up a controller to water the appropriate amount is actually much easier than it may seem when first attempting to balance the water between grass, flowers, vegetables, and all the fluctuating factors that you may encounter with your personal setup. Most of the models of controllers being used today can accommodate all the various needs of widely varying systems.
LifeSource Sprinklers 