Apparently its some weird scheme to help energy conservation. Article.
The change is mandated by the Energy Policy Act of 2005, signed into law by President George Bush on Aug. 8, 2005. The theory behind the change is that longer daylight hours contribute to saving money on electricity, as people use less electrical lights when the sun is shining.
But they say because it's three week earlier than normal, it'll screw up some people's toys. Article.