Put your timepieces on hold for an hour Sunday

Sir Isaac Newton didn’t know anything about shifting time, but his third law of motion might aptly describe a semi-annual manmade phenomenon: “For every action there is an equal and opposite reaction.”

In brief, it’s now time to undo what was done last spring, implementing “an equal and opposite reaction.” At 2 a.m. Sunday (earlier for those who don’t want to stay awake that long) Daylight Saving Time officially ends, and clocks should be set back one hour.

While the length of darkness and daylight won’t change much this weekend, daybreak and dusk will occur an hour earlier. Commuters will begin their daily drives under lighter conditions. Conversely, evening commutes will be under darker skies.

Most of the U.S. adopted the summer shift to Daylight Saving Time and will officially revert back this weekend. The exceptions are Arizona and Hawaii, American Samoa, Guam, Puerto Rico and the U.S. Virgin Islands, which don't observe Daylight Saving Time.

If you don’t want to wait until 2 a.m., feel free to reset your timepieces before retiring for the evening Saturday.

Whether you like or loath the semi-annual changes, you can blame/credit early American thinker Benjamin Franklin for conceiving it. According to National Geographic, Franklin considered the resource savings that could be achieved by spending more of our waking hours in daylight.

Most of the U.S. adopted the practice of shifting time with approval of the Uniform Time Act of 1966. It was implemented the following summer. Wikipedia provides a brief history:

Beginning in 1967, the act mandated standard time within the established time zones and provided for advanced time: clocks would be advanced one hour beginning at 2 a.m. on the last Sunday in April and turned back one hour at 2 a.m. on the last Sunday in October. States were allowed to exempt themselves from DST as long as the entire state did so. If a state chose to observe DST, the time changes were required to begin and end on the established dates.

In 1967, Arizona and Michigan became the first states to exempt themselves from DST (Michigan would begin observing DST in 1972). In 1972 the act was amended (P.L. 92-267), allowing those states split between time zones to exempt either the entire state or that part of the state lying within a different time zone. The newly created Department of Transportation (DOT) was given power to enforce the law.

Since 2007, daylight saving time starts on the second Sunday of March and ends on the first Sunday of November, with all time changes taking place at 2:00 A.M. local time.

Published 11-2-2012