I have not measured the water pressure that comes out of my faucet, but I turned the faucet on full when watering the lawn
This is a one time timer not programmable It won't do what you want for vacations.
Both. You can set the width by setting the angle of the jets, and the length by the rotation controls within limits. I can get about 35' long and maybe 28' wide when running one sprinkler at 60-70 pounds of water pressure. Length is the oscillating direction, width is set by the angle of the jets. In my narrower side yards, I set the width (angle of the jets) to 18'. The spray is an arc (semi circle), with the longest distance in the center of the arc, so it does not do perfect rectangles or square sides.If you want to do a 20'x15' area you have to set it so the outer (left and right) sides of spray of the arc meet this distance, meaning the center of the spray will have to exceed 20'. You can set the length down to about 0', straight up and down if you want.