Daylight Savings Time has often been touted as an energy saving measure. Research shows the benefits are mixed. Northern states that use less air conditioning may show improvements from extra evening light, but the majority of the US will show higher energy use from increased air conditioning demands.
In addition, adding additional darkness in the morning creates higher energy use from lighting, therefore offsetting the potential evening benefit.
Humans may suffer health problems due to the shifting clock. There is evidence that circadian rhythms, the internal processes that regulate body functions, may be negatively affected by shifting clocks back and forth.
Farmers are negatively affected by DST. Working in morning darkness creates additional burdens for adding sufficient lighting.