Daylight Saving Time: Overview

Introduction

Daylight saving time (DST) is a method of energy conservation accomplished by advancing clocks so that afternoons have more daylight and mornings have less. The term, daylight saving time, uses the word saving as an adjective, as in labor-saving device. In some uses, the first two words are hyphenated, as in daylight-saving time. Daylight savings time, daylight savings, and daylight time are common variations used by many people, with the use of the word savings referring to something similar to a savings account. The slogan, “spring forward, fall back” helps people remember to put their clocks forward in the spring, and back in the autumn.

Besides conserving energy by allowing businesses such as retailing and sports to reduce the amount of time they must light and heat their facilities, studies have shown that the observation of DST has also helped to decrease traffic-related accidents. In 1995 the Insurance Institute for Highway Safety estimated a reduction of 1.2%, including a 5% reduction in crashes fatal to pedestrians. Participation in outdoor activities also tends to increase because of extended daylight hours. During wars and times of economic crisis, daylight saving time has been used for extended periods for additional energy savings, as well.

Critics of daylight saving time express concern over safety and productivity in the early morning hours, particularly for students and farmers who are required to be outdoors before sunrise on the DST system. Some critics are opposed to DST as it relates to the entire global time system and would prefer the implementation of coordinated universal time (UTC) to dictate local time and events.

The changeover hour for daylight saving time is typically in the early morning. In the United States, DST begins and ends at 2 a.m. This particular hour was chosen because it is late enough to minimally affect bars, restaurants, and shift workers; it prevents the current day from switching to the previous day, and it is early enough that the entire continental US can effectively switch times by daybreak.

Understanding the Discussion

24-Hour Clock: A method of keeping time which assigns a different number to each hour of the day. This differs from a standard clock, which repeats a twelve-hour cycle and distinguishes between ante meridiem (a.m.) and post meridiem (p.m.). Ante meridiem is Latin for “before noon” and ante meridiem is Latin for “after noon.”

Coordinated Universal Time (UTC): The time set at zero longitude which serves as the basis for the global system of time-keeping. It is monitored by time laboratories around the world and determined using highly precise atomic clocks. This time is usually given in terms of a 24-hour clock.

Greenwich Mean Time (GMT): The universal time as it is monitored by the Royal Observatory in Greenwich, England, at zero longitude.

Standard Time: The time set throughout each time zone across the US when DST is not in effect.

Time Zones: Any of the twenty-four regions of the globe that have adopted the same standard time. Each of these zones differs from neighboring zones by exactly one hour.

History

Daylight saving time was first suggested in April 1784, by Benjamin Franklin in his essay “An Economical Project for Diminishing the Cost of Light” published in the Journal de Paris. Franklin noted fuel expenses as they related to the extensive Parisian nightlife, and proposed the time adjustment so that individuals and businesses could take advantage of natural daylight in the evening and save on the cost of candle wax.

More than a century later, in the spring of 1916, Franklin’s idea became a reality in most of Europe as countries adopted daylight saving time to save fuel used to produce electricity. A similar law, “An Act to save daylight and to provide standard time, for the United States” was adopted in America on March 19, 1918. The law established the five standard time zones and set DST to be practiced for seven months in 1918 and 1919. The DST adjustment was so unpopular, particularly with farmers, that the law was repealed in 1919, with a local option for regions to remain under the program as they wished. States such as Massachusetts and Rhode Island decided to continue on the DST system, as did some cities, including New York, Philadelphia, and Chicago.

In 1942, daylight saving time was reinstituted on a year-round basis by President Franklin Roosevelt, who renamed the effort “war-time.” This special observation of daylight saving time lasted until the end of World War II in September 1945.

From 1946 to 1966 there were no federal laws in the United States regarding daylight saving time. Regions around the country practiced DST according to local preferences. This caused great difficulties for the broadcast industry, and for trains, buses, and other transportation services.

In 1966, Congress resolved these local time discrepancies with the Uniform Time Act, which detailed the implementation of a national daylight saving time to begin on the last Sunday of April and end on the last Sunday of October. Areas wishing to be exempt from the new law were permitted to pass local ordinances in accordance with their time preferences. Arizona, Hawaii, and eastern portions of Indiana opted out of the new law.

In 1973, in response to an international oil crisis, Congress extended DST for a two-year period, hoping to save additional energy. During this time, the US Department of Transportation conducted a study on the effects of daylight saving time. According to this study, the implementation of DST for the additional two months of March and April reduced oil usage by 600,000 barrels per year, saved fifty lives, prevented 2,000 injuries, and saved $28 million in traffic accident costs. Nevertheless, the experiment was cut short in 1975 in response to opposition by farmers and parents who were concerned over the loss of early morning light for work and safety purposes.

In 1986, DST was altered slightly to take advantage of additional energy saving for the entire month of April. Rather than beginning the annual program on the last Sunday in April, it was adjusted to begin on the first Sunday of the month.

While many critics of daylight saving time simply dislike the disruption of changing the clocks twice a year, some claim the entire global system of time-keeping is antiquated. Rather than time zones, standard time, and DST, they favor the use of a Coordinated Universal Time (UTC), which they argue is more appropriate for an era that includes diverse global communication via the internet and other technologies.

UTC, or the 24-Hour Clock, is also known by civilians as Greenwich Mean Time (GMT), and by those affiliated with the military and aviation as Zulu. With this system, individual communities would determine local start times for all types of events according to a universal time rather than relating a given hour to a set amount of daylight. For instance, a morning event in Japan, such as the starting of the school day, might start at 1600 hours and the changing of the day might happen during what in Japan might be considered the mid-afternoon. Under a Universal Coordinated Time system, DST is not needed as such, but might be utilized should local communities decide to change their schedules throughout the year to account for changes in sunlight.

During the summer of 2005, changes to DST were established on both federal and state levels in the United States. Indiana passed a revised state ordinance calling for the entire state to begin observing DST as of April 2006. In addition, the Energy Policy Act of 2005 was passed by Congress and signed by President George W. Bush, extending DST by one month beginning in the spring of 2007. On the revised schedule, DST begins on the second Sunday of March and ends on the first Sunday in November.

Although the plan to change the dates for daylight saving time was widely favored, some groups have particular issues regarding the adjusted schedule. School boards and parents raised concerns that the later sunrise would leave many school-aged children waiting for school buses in the dark. Meanwhile, critics in the airline industry complained that the adjusted DST would cost them millions of dollars in flight schedule changes. In the computer industry, the change in DST meant patching and reprogramming all date-sensitive hardware and software keyed to the existing DST schedule. The 2007 schedule change also prompted DST revisions in Canada, in an attempt to avoid difficulties in its commerce and communications with the US.

Daylight Saving Time Today

Around the world, DST is observed by a variety of nations and regions. The European Union practices DST from the last Sunday in March to the last Sunday in October. China, which has functioned under a single time zone since 1980, observed DST from 1986 through 1991, but then ceased the practice. In the Southern Hemisphere, nations such as Australia and New Zealand do practice DST, but their start and end dates run opposite those of the Northern Hemisphere. Nations along the equator and in tropical regions typically do not practice DST because daylight hours remain constant in those locations throughout the year.

A poll conducted by the Associated Press and the National Opinion Research Center (NORC) at the University of Chicago found that in 2019, 40 percent of Americans wanted to institute year-round standard time while 31 percent wanted to make DST permanent; only 28 percent desired to have the practice of changing the clocks twice per year stay the same.

However, by early 2024 in the United States, Arizona and Hawaii remained the only states to have opted out of adhering to DST, but the debate about whether to change to either permanent daylight saving time or year-round standard time instead was ongoing in several of the remaining states. According to the National Conference of State Legislatures, legislators in at least nineteen states had proposed legislation to enable DST year-round by early 2024. The US territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the US Virgin Islands continued to opt out of adhering to DST through early 2024.

Previously, in 2022, the US Senate unanimously voted in favor of the Sunshine Protection Act, which, if passed, would permanently implement DST in states that observe it. At the same time, a 2022 poll conducted by CBS News revealed that nearly 80 percent of Americans supported a modification to the established DST schedule, with 46 percent supporting permanent DST and 33 percent supporting permanent standard time. However, by early 2024, the Sunshine Protection Act had yet to pass the US House of Representatives.

These essays and any opinions, information or representations contained therein are the creation of the particular author and do not necessarily reflect the opinion of EBSCO Information Services.

Bibliography

Åries, M. & Newsham, G. “Effect of Daylight Saving Time on Lighting Energy Use: A Literature Review.” Energy Policy, vol. 36, no. 6, 2008.

Choi, Charles Q. “Spring Forward or Not?.” Scientific American, vol. 300, no. 3, 2009, pp. 18–19. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=aph&AN=36394225&site=ehost-live. Accessed 8 June 2009.

“Clock-Watching.” Nature, 25 Jan. 2007, pp. 339+. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=aph&AN=23792231&site=ehost-live. Accessed 8 June 2009.

"Daylight Saving Time vs Standard Time." The Associated Press-NORC Center for Public Affairs Research, www.apnorc.org/projects/Pages/Daylight-Saving-Time-vs-Standard-Time-(2019).aspx. Accessed 17 Apr. 2020.

De Pinto, Jennifer. "More Americans Prefer Daylight Saving Time to Standard Time - CBS News Poll." CBS News, 9 Apr. 2022, www.cbsnews.com/news/more-americans-prefer-daylight-savings-to-standard-time-cbs-news-poll/. Accessed 22 Mar. 2024.

Latson, Jennifer. “When Daylight Saving Time Was Year-Round.” Time.com, 12 Feb. 2015. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=100947371. Accessed 9 Nov. 2015.

Lowenberg, Olivia. “Daylight Saving Time: Why It Isn’t Going Away.” Christian Science Monitor, 31 Oct. 2015. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=pwh&AN=110635112&site=pov-live. Accessed 9 Nov. 2015.

Pavlus, John. “Daylight Savings Time.” Scientific American, vol. 303, no. 3, 2010, p. 69. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=52888721&site=ehost-live. Accessed 3 Jan. 2013.

Reed, Jim. "Love It or Hate It, Daylight Saving Time Is Here Again." National Conference of State Legislatures, 7 Mar. 2024, www.ncsl.org/state-legislatures-news/details/love-it-or-hate-it-daylight-saving-time-is-here-again. Accessed 22 Mar. 2024.

Rothman, Lily. “When Daylight Savings Time Was Illegal.” Time.com, 10 Mar. 2015. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=a9h&AN=101462927. Accessed 9 Nov. 2015.

Seppa, Nathan. “Daylight Saving Time Tied to More Exercise in Children.” Science News, 29 Nov. 2014, p. 16.

Sexton, Alison L., and Timothy K. M. Beatty. “Behavioral Responses to Daylight Savings Time.” Jour. of Economic Behavior & Organization, vol. 107, 2014, pp. 290–307.

Sissine, Fred. “Energy Efficiency and Renewable Energy Legislation in the 109th Congress: RL32860.” Congressional Research Service: Report, 9 Feb. 2006, pp. 1–49.

Slisco, Aila. "Utah and Maryland Could Become Latest States to Move to Permanent Daylight Saving Time." Newsweek, 5 Mar. 2020, www.newsweek.com/utah-maryland-could-become-latest-states-move-permanent-daylight-saving-time-1490619. Accessed 17 Apr. 2020.

Temescu, LeeAundra. “20 Things You Didn't Know about Time.” Discover, vol. 30, no. 3, 2009, p. 80. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&db=aph&AN=36455432&site=ehost-live. Accessed 8 June 2009.

Urbatsch, R. “Time Regulations as Electoral Policy.” American Politics Research, vol. 42, no. 5, 2014, pp. 841–55.