One to three working days for most Spokane homes. Larger or trickier lots can stretch to four or five days. The best time to install is between spring and fall when the ground is workable; on a rebuild, irrigation goes in after grading and before sod, seed or planting.
Install day covers trenching, pipe, valves, heads, the backflow assembly and the controller, then a walkthrough so you know how it runs and where every valve is.