Sunday is when we pay back that extra hour of sleep we earned last fall, daylight saving time again resetting our inner and outer clocks for a bit of extra sunlight in the evening. But even as the days get longer, it won’t feel as much like spring with the return of winter temperatures in the days ahead. As we undergo the biannual ritual of turning clocks ahead (spring) and back (fall), it begs the question: Why do we do this?