Per the Energy Policy Act of 2005, this began March 11, 2007, 3 weeks earlier than in 2006
[DOC] [TLE] Daylight Time - Astronomical Applications Department [PAR] As of 2007, daylight time begins in the United States on the second Sunday in ... 
On the second Sunday in March, clocks are set ahead one hour at 2:00 a.m. local 
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