Why are there eight months of daylight saving each year?

It wasn't always this way.

We started with six months in the 1960s, then moved to seven in the mid-1980s. Now, we spring forward an hour in March and don't fall back until early November.

The most vocal lobby pushing for longer periods of daylight time has been the chambers of commerce. - Michael Downing, author

There's a pervasive misconception that this helps farmers. It doesn't. Farmers have been outspoken critics of daylight time since the idea picked up steam in the early 20th century.

Governments have long sold daylight time as a way to conserve energy. If we spend more waking hours in sunlight, we'll use less electricity to light our homes. Or so the idea goes.

But according to Tufts University professor Michael Downing, author of Spring Forward: The Annual Madness of Daylight Saving Time, there's more to the story.

"In the U.S. and also in Canada, the most vocal lobby pushing for longer periods of daylight time has been the chambers of commerce," he said.

Commerce benefits

Studies suggest that consumers are more inclined to go out and spend money if there's more daylight after they leave work. But retailers and business owners knew that long before science backed the idea up, says Downing.

Take, for example, the most recent extension of daylight time. It came as part of the U.S. Energy Policy Act of 2005, a law ostensibly aimed at boosting energy conservation. A provision in the act pushed the start of daylight time from the first Sunday in April to the second Sunday in March, and the fall back to standard time from late October to early November.

It took effect in 2007, and the parts of Canada that use daylight time also adopted the new parameters at that time.

Daylight time first came to North America during the First World War, but it was ditched shortly after the war ended. It wouldn't make a comeback until 1966, when the U.S. government tried to calm the chaos caused by having different parts of the country using their own versions of daylight time. (National Archives and Records Administration/Wikimedia Commons)

Industry groups representing big-box stores, sporting and recreational goods manufacturers, barbecue and charcoal retailers, shopping malls and golf courses all lobbied the U.S. Congress to extend daylight time.

Downing is quick to point out the lobbying efforts are public and that most industry groups are very open about their involvement. Their endeavours are part of a long history of business interests pushing for daylight saving time.

A. Lincoln Filene, owner of the now-defunct U.S.-based Filene's department store chain, founded the National Daylight Saving Association — perhaps the first organized daylight time lobby group — in 1917, writes Mike O'Malley, a professor of American history at George Mason University in Virginia.

Among its biggest supporters were professional baseball leagues (afternoon games could be scheduled after work hours) and garden-supply retailers.

Unforeseeable consequences

But as some modern-day businesses profit from a longer daylight saving period, those benefits are "offset by the law of unforeseeable consequences," says Matthew Rosza, a doctoral student in history at Lehigh University in Pennsylvania and a political columnist.

Rosza spent about a year researching the history of daylight time for a piece published in Salon in 2014.

Adjusting the clocks twice a year "is one of those rituals that seems to make sense based on folksy wisdom, but when you study the science behind it, it doesn't," he said.

Former U.S. president George W. Bush passed the Energy Policy Act into law in 2005. It would extend daylight time to eight months. (Kevin Lamarque/Reuters)

There are conflicting findings on the question of whether daylight time really conserves energy. Studies done for Congress have tended to report small savings, but others done at the state level and by independent researchers did not.

One of the most definitive studies examined electricity use in Indiana. It was a perfect test case because, prior to 2006, many areas of the state did not use daylight time. But that year, it was adopted in every county, which gave researchers an opportunity to compare before-and-after data

While electricity demand for lighting decreased in the evening, the extra hour of sunlight meant Hoosiers kept their air conditioners pumping for longer each day. In the end, the average household used more electricity after daylight time kicked in.

There's a persistent myth that daylight time helps farmers when, in fact, the agricultural sector is among the most vocal critics of the practice. For example, it throws off milking schedules for dairy cows. (Christinne Muschi/Reuters)

Further, a statistical analysis done in California found that the 2007 extension of daylight time had "little or no effect on energy consumption" in the state.

'They're going to drive'

According to Downing, there is another important consequence.

"People are going to use more evening light and enjoy it," he said. "They go out to shop, to the park, to sporting events — but they aren't going to walk. They're going to drive. Gas companies have known this dating back to the 1930s."

He notes that a prominent lobby group pushing for more daylight time is the National Association of Convenience Stores, which represents many businesses that are affiliated with gas stations.

In 2001, a senior U.S. Department of Transportation official testified before Congress that it's entirely possible that any energy savings from daylight time could be offset by increased travel but cautioned there was a dearth of data on the subject.

The U.S. Department of Transportation has suggested daylight time might lead to more travel, in turn increasing gas consumption. (Michelle Siu/Canadian Press)

For his part, Downing supports the idea of shifting back to six months of daylight time. Keeping it year-round would mean extremely late winter sunrises for many people, particularly in the west, he said. (Though there is a compelling case for a move a to permanent daylight time.)

Downing says one of the biggest problems with daylight saving time is that it gives governments an excuse to avoid having to develop a "real mechanism to reduce energy consumption."

"Daylight saving time has become a damaging substitute for any meaningful energy policy," he said.