robert bazell presents the results of a study of thousands of people in sweden into the health effects of daylight saving time.
in the two weeks after the spring change, when people lose an hour of sleep -- heart attacks go up by five percent (5%). conversely, in the two weeks after the fall change back to standard time, when people gain an extra hour of sleep -- heart attacks go down by five percent (5%).Starting in 2007, daylight time begins in the United States on the second Sunday in March and ends on the first Sunday in November. On the second Sunday in March, clocks are set ahead one hour at 2:00 a.m. local standard time, which becomes 3:00 a.m. local daylight time. On the first Sunday in November, clocks are set back one hour at 2:00 a.m. local daylight time, which becomes 1:00 a.m. local standard time. These dates were established by Congress in the Energy Policy Act of 2005, Pub. L. no. 109-58, 119 Stat 594 (2005).
Not all places in the U.S. observe daylight time. In particular, Hawaii and most of Arizona do not use it. Indiana adopted its use beginning in 2006. ~ read more
