The current Daylight Saving Time schedule was extended by about 30 days by the Energy Policy Act of 2005 in an effort to save energy. But researchers at TreeHugger found that Daylight Saving Time increases electrical demand, “as air conditioning has eclipsed lighting as the main use of energy.”
Moreover, DST can have mixed effects on the economy depending on industry – theaters and television shows will lose audience as people go out and enjoy the evening air, while retailers and the golfing industry will benefit from people going out later.
Read more at Treehugger.