Sure you can enjoy one more hour of sleep when you turn the clock back one hour on Sunday, but it also means less afternoon daylight during all those bleak winter months. A recent commentary in the British Medical Journal says that people will fill an extra daylight hour with physical activity instead of going into hibernation mode. 

People tend to be more active during the long, bright days of summer but more depressed and sedentary during the short, dark days of winter, the author, Mayer Hillman writes.  Hillman, a senior fellow at the Policy Studies Institute at the University of Westminster, estimates that about 300 more hours of daylight a year could be created by not setting the clock back in the fall but still setting it forward in the spring. The estimate is based on people’s typical activity patterns. For children, who tend to go to bed earlier, it would be closer to 200 extra hours.