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| Photo: Ileana Johnson 2015 |
At 2 a.m. on
the second Sunday in March until 2 a.m. on the first Sunday in November, all
states except Arizona, Hawaii, and territories, American Samoa, Guam, the
Northern Mariana Islands, Puerto Rico, and the Virgin Islands observe DST.
Seventy other nations around the world also follow DST.
Benjamin
Franklin, then Minister to France, proposed in 1784 to reset the clocks when
the sun came up and people were still sleeping, saving one million francs per
year in candles.
A British builder, William
Willett, proposed in 1907 to move hours of work and recreation more closely to
daylight hours, cutting back on artificial light. The bill he proposed in
Parliament did not pass.
To conserve fuel, Germany started
DST on May 1, 1916. During the war, most of Europe also adopted DST.
In the U.S., DST was not formally
adopted until March 19, 1918, establishing both standard time zones and summer
DST to start on March 31, 1918. Because the idea was unpopular, Congress
abolished DST after the war, overriding President Woodrow Wilson’s veto. Some
states observed DST until WW II. At that time, President Franklin Roosevelt
established “War Time” on February 9, 1942 which ended on the last Sunday in
September 1945. The following year, many states adopted summer DST.
According to the Congressional
Research Service, the Uniform Time Act of 1966 (P.L. 89-387) established
federal regulation across the country because the transportation industry
needed consistency in time observance. Clocks were to be set forward one hour
on the last Sunday in April at 2 a.m. and set back on the last Sunday in
October. An entire state could exempt itself from the law, including states
that were located in split time zones, as long as the entire state would follow
the same time. Arizona exempted itself in 1968 and in 1972 the act was amended
to allow states split in different time zones to be exempted or be entirely
included in DST. The Department of Transportation became the law’s enforcer.
The OPEC oil embargo of 1973
prompted Congress to have a trial period of year-round DST in order to conserve
energy and fuel. Benefits advertised were more recreation, reduced light and
heating demand, reduced crime, and reduced auto accidents. Many worried about
children going to school in the dark. After the trial period, in 1975 the whole
country returned to DST.
The DOT found that “modest overall
benefits might be realized by a shift from the historic six-month DST (May
through October) in areas of energy conservation, overall traffic safety and
reduced violent crime” when the DST was proposed to be changed to
March-November.
Beth Cook wrote that the DOT
reported, “These benefits were minimal and difficult to distinguish from
seasonal variations and fluctuations in energy prices.” (March 9, 2016, CRS,
R44411, p. 2)
Cook also wrote, “Congress then
asked the National Bureau of Standards (NBS) to evaluate the DOT report. In an
April 1976 report to Congress, Review and Technical Evaluation of the DOT
Daylight Saving Time Study, NBS found no significant energy savings or
differences in traffic fatalities. It did find statistically significant
evidence of increased fatalities among school-age children in the mornings
during the four-month period January-April 1974 as compared with the same
period (non-DST) of 1973. NBS stated that it was impossible to determine, what
if any of this increase was due to DST. When this same data was compared
between 1973 and 1974 for the individual months of March and April, no
significant difference was found for fatalities among school-age children in
the mornings.” http://www.fas.org/sgp/crs/misc/R44411.pdf
The Uniform Time Act of 1966 was
modified in 1986 to change DST to first Sunday in April through last Sunday in
October and in 2005 when Congress changed DST to second Sunday in March and
ending it the first Sunday in November. Congress also asked the Department of
Energy (DOE) to report on the impact of extended DST on energy consumption. DOE
sent this report to Congress in 2008. (Fred Sissine, CRS RL32860, Energy
Efficiency and Renewable Energy Legislation in the 109th Congress)
Cook enumerated some studies on
energy savings, health, and safety:
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Department
of Energy (DOE) studies in 2006 and 2008 revealed that ”Total potential electricity
savings benefits of DST are relatively small, 0.01 percent to 0.03 percent
of total annual U.S. energy consumption.” http://www1.eere.energy.gov/ba/pba/pdfs/epact_sec_110_edst_report_to_congress_2008.pdf
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“There is
general consensus that DST does contribute to an evening reduction in peak
demand for electricity, though this may be offset by an increase in the
morning.” (M.B. Aries and G.R. Newsham (2008), “Effect of Daylight Saving Time
on Lighting Energy Use: A Literature Review,” Energy Policy, 36(6),
1858–1866.)
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“Our main finding
is that, contrary to the policy’s intent, DST increases electricity demand.” A
trade off was identified between “reducing demand for lighting and increasing
demand for heating and cooling.” http://environment.yale.edu/kotchen/pubs/revDSTpaper.pdf
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A. Huang and D.
Levinson, studying the effects of DST on vehicle crashes in Minnesota, found in
2010 that “the short term effect of DST on crashes on the morning of the first
DST is not statistically significant.” http://nexus.umn.edu/papers/daylightsavingstime.pdf
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T. Lahti et al
found in their 2010 study, “Our results demonstrated that transitions into and
out of daylight saving time did not increase the number of traffic road
accidents.” (T. Lahti et al., 2010, “Daylight Saving Time Transitions and Road
Traffic Accidents,” Journal of Environmental and Public Health, 657167)
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Y. Harrison found
in his 2013 that “The start of daylight saving time in the spring
is thought to lead to the relatively inconsequential loss of 1 hour of sleep on
the night of the transition, but data suggest that increased sleep
fragmentation and sleep latency present a cumulative effect of sleep loss, at
least across the following week, perhaps longer. The autumn transition is often
popularized as a gain of 1 hour of sleep but there is little evidence of extra
sleep on that night. The cumulative effect of five consecutive days of earlier
rise times following the autumn change again suggests a net loss of sleep
across the week. Indirect evidence of an increase in traffic accident rates,
and change in health and regulatory behaviors which may be related to sleep
disruption suggest that adjustment to daylight saving time is neither immediate
nor without consequence.” http://europepmc.org/abstract/MED/23477947
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MR Jiddou et al in their 2013 study, “Incidence
of Myocardial Infarction with Shifts to and From Daylight Savings Time,” The American Journal of Cardiology,
111(5), 631-635, stated, “Limited
evidence suggests that Daylight Saving Time (DST) shifts have a substantial influence
on the risk of acute myocardial infarction (AMI). Previous literature, however,
lack proper identification necessary to vouch for causal interpretation. We
exploit Daylight Saving Time shift using non-parametric regression
discontinuity techniques to provide indisputable evidence that this abrupt
disturbance does affect incidence of AMI.”
If savings in electricity are relatively small, cumulative sleep
deprivation has been demonstrated which could result in productivity loss and
traffic accidents, and potential health effects, why are we embracing DST?
Wouldn’t following nature’s biological clock be more beneficial to our
wellbeing?
