Erwin runs on two calendars — the green one that starts when the valley thaws, and the white one that takes over about the time the Gang Mills lights come on at four in the afternoon. First Choice Lawn & Snow LLC works both: mowing, edging, trimming and cleanups through the warm months, then plowing, shoveling and salting once the Tioga valley locks up. The same driveway that gets mowed alongside in July gets opened up in January, which is a fine way to learn a property inside out. Fall is the hinge — leaves off, beds closed, equipment swapped, everything staged for the first storm coming down off the hills. Then the year turns over and it all begins again.