In This Article
30-Second Summary
Headline Links: Daylight-saving time impact
Background: Energy Policy Act of 2005, official U.S. time and smart clock problems
History: Daylight-saving time, 1966 Uniform Time Act, and Benjamin Franklin
Opinions & Analysis: The candy lobby, and how much energy is actually saved
Reference Material: Computerized devices and international observation
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Daylight-Saving Time Changed for First Time in Twenty Years
by
findingDulcinea Staff
Congress enacts new rules for daylight-saving time, expanding the daylight-saving period so that it now begins three weeks earlier, on the first weekend in March, and ends one week later, in the first week in November.
30-Second Summary
For the first time in more than 20 years, the rules for daylight-saving time changed, on Aug. 8, 2005. The new time-keeping convention came into effect for the fist time this year.
Previously clocks were set forward one hour on the first Sunday in April and set back one hour on the last Sunday in October.
The result of this yearly time-shift is to move one hour of sunlight from the morning to the evening. The reason behind this shift is often debated; yet, most agree that one goal is to save money on energy.
Although Congress passed the Uniform Time Act of 1966, which standardized the start and end of daylight-saving time, federal law does not make it mandatory for any area to set the clocks back each year. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and the state of Arizona do not observe daylight-saving time.
Previously clocks were set forward one hour on the first Sunday in April and set back one hour on the last Sunday in October.
The result of this yearly time-shift is to move one hour of sunlight from the morning to the evening. The reason behind this shift is often debated; yet, most agree that one goal is to save money on energy.
Although Congress passed the Uniform Time Act of 1966, which standardized the start and end of daylight-saving time, federal law does not make it mandatory for any area to set the clocks back each year. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and the state of Arizona do not observe daylight-saving time.
Headline Links: Daylight-saving time impact
Congress enacted the new daylight-saving time rules in 2005, but these rules were set to take effect in 2007 instead to allow enough time for computer problems to be worked out. The Consumers Electronics Association has stated that most consumers will be unaffected by the new DST rules because most time-dependent products receive time and date from a network.
Source: Market Watch
The body’s internal clock is controlled by the circadian rhythm, which determines when people are sleepy or alert and when they want to eat. A new German study shows that the “normal correlation between dawn and the sleep cycle becomes disrupted during the transition to daylight-saving time.”
Source: Slate
Background: Energy Policy Act of 2005, official U.S. time and smart clock problems
In Aug. 2005, Congress passed the Energy Policy Act of 2005, which extended daylight-saving time by three weeks in the spring and one week in November to reduce energy consumption by approximately 100,000 barrels of oil for each day of the extension. In addition, Congress asserted that according to several studies, an extended DST would lower crime and traffic fatalities as well as increase economic activity.
Source: United States Senate Committee on Energy & Natural Resources
The Role of NIST
The National Institute of Standards and Technology (NIST) keeps the official U.S. time, yet DST time and time zones are controlled by the U.S. Department of Transportation. DST begins at 2 AM on the second Sunday of March, during which clocks are set ahead one hour, and ends at 2 AM on the first Sunday of November when clocks are set back one hour. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and the State of Arizona do not observe DLS.
Source: National Institute of Standards and Technology
National Institute of Standards and Technology provides the official local time for each U.S. time zone.
Source: National Institute of Standards and Technology
Tom O’Brien, who works for the National Institute of Standards and Technology, explains why Smart clocks, which would normally automatically adjust for daylight-saving time, are not able to do so this year. “These are clocks that basically have a battery in them, they are pre-set at the factory for the correct time, built into these clocks are the rules for daylight-saving time time, if you bought these clocks a few years ago it has the old rules … unfortunately that is hard wired into the clock itself.”
Source: National Pubic Radio
History: Daylight-saving time, 1966 Uniform Time Act, and Benjamin Franklin
Bill Mosley, a public affairs officer at the U.S. Department of Transportation, explains that the history of Daylight-saving time begins with the railroads. "In the early 19th century … localities set their own time. It was kind of a crazy quilt of time, time zones, and time usage. When the railroads came in, that necessitated more standardization of time so that railroad schedules could be published.” Yet, it wasn’t until 1966 that Congress passed a Uniform Time Act, which standardized the start and end times for daylight-saving time uniform rules were set for clocks across the nation.
Source: National Geographic
From Unpopular Origins to Standardization
According to Webexhibits, a 1918 Act, which set standardized time zones and set DLS time, was repealed the following year because it was so unpopular after that DLS became optional. DST remained optional until Word War II when President Franklin Roosevelt mandated it. After 1966, when it was standardized, most of the country started to follow DST. Webexhibits is supported by the Institute for Dynamic Educational Advancement and the U.S. Department of Commerce, National Institute for Standards and Technology (NIST).
Source: Webexhibits
Benjamin Franklin is credited with first thinking of saving daylight hours by adjusting the clocks twice a year. In 1784, Franklin wrote an essay entitled “An Economical Project” while living in Paris, which advocates the use of natural light over artificial light as a means to save money.
Source: Webexhibits
Opinions & Analysis: The candy lobby, and how much energy is actually saved
The Cityroom blog speculates that Michael Downing might be on to something in asserting that the extra hour of Daylight-saving time this year is due in part to lobbying by the Confectioners Association, who according to Downing, thought an extra hour of light for trick-or-treating would spur more candy sales.
Source: Cityroom Blogs New York Times
Carl Bialik of the Wall Street Journal questions how much energy is saved by changing the clocks.
Source: The Wall Street Journal
Reference Material: Computerized devices and international observation
Microsoft offers a “Daylight Saving time Time Update Guide” for users concerned about computer’s calendars and clocks.
Source: Microsoft
CNET explains how the new rules for Daylight-saving time will impact computerized devices and what needs to be done to avoid any problems.
Source: CNET News
Webexhibits offers a list of most of the countries that observe daylight-saving time around the world. China, India and Japan are the only major industrialized countries that do not observe daylight-saving time.
Source: Webexhibits
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