This Sunday, we’ll spring ahead for daylight saving time — but why?
While many people experience short-term grogginess following the time change, the observation of daylight saving time extends the amount of daylight to allow for more productivity. Allen Goodman, professor of economics, discusses the history and impact of daylight saving time.
Q: What are standard time and daylight saving time?
A: The idea of standard time is a very old notion — it bases time within a geographical area to a single time standard, rather than having noon when the sun is overhead. In contrast, daylight saving time advances clocks at the start of spring so that evening daylight lasts longer. While DST is nationwide, two states — Arizona and Hawaii — have opted out of daylight saving time, and in several states, certain areas — like the Indiana counties close to Chicago — adjust their time to align to the economic center of their region.
Q: What can you tell us about the history of standard time and daylight saving time?
A: A major factor in establishing standard time in the United States and Canada was the railroad industry — it was necessary to ensure schedules aligned and no more than one train was on the same tracks at the same time. When standard time was established in 1883, there was a lot of opposition. Prior to that, time was generally treated as a local matter. Daylight saving time was developed and first used in Germany during World War I, with the idea of minimizing the use of artificial lighting to save energy for the war effort and to have the timing of the sunlight be more convenient for daytime activities. During the first U.S. energy crisis in the 1970s, a similar thought prevailed: Switching to daylight saving time all year would allow people to use less energy. In 1974, Congress proposed daylight saving time year round, but this was changed before the proposed demonstration period — January 6, 1974, through April 27, 1975 — had finished. In reality, the impact was insignificant; people may have heated their homes less, but they used more air conditioning. In 2007, daylight saving time was extended from early March to late October or early November.
Q: Are there noted impacts beyond the physical and economic impacts?
A: Studies published in economic journals discovered a 7 percent decrease in robberies following the shift to daylight saving time, assumedly because robbers prefer to operate in the dark.
Is there a reason the time change always occurs on a Sunday?
A: Scheduling the time change on a Sunday lessens the impact because typically traditional work is conducted during the week rather than on a weekend. If there’s got to be a day with 23 hours rather than 24, a Sunday makes the most sense for most people.