The Energy Policy Act of 2005 extended day light saving time by 4 weeks. This allegedly was done to save energy costs. The other major motive that policy makers will not admit is that having an extra hour of daylight will benefit retailers because people will be more likely to go to the malls to shop or out to eat after work if it is light outside. Ironically this will most likely lead to more driving and thus more energy being used. But, I am not complaining because the extra hour of day light at night makes it easier for me to ride by bike to and from work.   For the Policy nerds out there, here is the URL to read the exact text of the entire Energy Policy Act of 2005: http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=109_cong_public_laws&docid=f:publ058.109