Snow falling on Royal Oak at midnight takes the sound out of the streets; even Woodward goes soft a few blocks away. Serene Lawn-N-Snow Outdoor Services works in that hush, plowing drives, shoveling porches and walks, laying salt where ice would otherwise set up by morning. In summer the calm hour sits at the other end of the clock, early, when the mowing and trimming and edging get done ahead of the heat and the traffic. Both hours have the same appeal: a property put right while the neighborhood is still asleep. People wake to it and never see how it happened.