Debunking the myths about Daylight Savings Time

Last night, we will pushed our clocks forward one hour, to celebrate the coming of Daylight Savings Time, nearly a month earlier than we've ever done it before.

DST was originally proposed by a British nobleman named William Willett. Willett became irked that his hunting and golf was cut unnecessarily short in the summer months. He unsuccessfully lobbied for the concept until his death.

Years later, Germany picked up on his theories during WWI, and along with its allies, implemented it in the name of saving energy. The theory was that one hour less of lightbulbs would be used at night and give the allies an energy surplus they could use to their advantage.

Decades later, there is extensive myth and controversy surrounding the practice. Let's have a look at the facts and fiction:

#1: DST creates an extra hour of daylight
Myth. Is this really something I need to address? Seriously? Apparently so. There are a series of internet memes floating around that DST creates more daylight, and thus contributes to global warming. Sigh. C'mon people. It shifts the clock, it doesn't alter time and space.

#2: DST has a deleterious impact on animals and crops
Myth. Animals and crops have no idea DST is even happening. Unless it's in a Gary Larson cartoon, cows do not wear wristwatches. It's the way in which each individual farmer implements the DST shift that could have an impact. If a dairy farm changes their clocks, and then starts milking their cows an hour later, then there can be health impacts for the animals. If they gradually shift the time they start milking the cows, to take advantage of the extra sunlight summer brings and start their farm operations earlier, the cows are just fine.

#3: DST saves energy
Myth. There may have been a time and a place that DST saved energy, but I am extremely sorry to report that this is no longer the case. Australia implemented DST in 2000 and tracked the results very closely, as did the state of Indiana in 2006. In both cases, they found no net energy savings, and in some cases, an increase in energy usage. Lighting usage did go down, but this was completely washed away by increases in air conditioning and gasoline consumption for cars.

#4: DST reduces traffic accidents and crime.
Fact and Inconclusive. The Indiana and Australia data did show a marked decrease in traffic accidents when DST was implemented. Data on crime was less clear.

#5: DST increases our health.
Inconclusive. While certainly there are physical and emotional benefits to not having it be pitch black when you drive home from work (namely Vitamin D production, the tendency to take up outdoor activity, and lower Cholesterol), the switch itself takes many people weeks to adjust to, throwing off their circadian rhythms, disrupting sleep patterns, and creating health problems where there were none. Experts say it's a draw.

Net net, when you look at the cold, hard data, Daylight Savings Time seems to have very few benefits. So why are we still doing it and even expanding its usage?

Another perplexing question is why we don't just shift our work hours one hour back in the summer, rather than springing the clocks forward. Doing so would have the same 'happiness' impact and eliminate the complexity of dealing with our clocks. Did Dolly Parton's "Working 9-5" song lodge itself so firmly in our cultural credos that we cannot possibly exorcise it?

To seek the answer, we have to look at who is benefiting from the extended DST period. In fact, it was the Sporting Goods Manufacturing Association and the National Association of Convenience Stores that lobbied Congress in 2005 to extend DST. 7-11 alone stands to gain $30 million extra in revenue this year from the time shift.

And dang it, even knowing all of this, I can't help but be excited that I just switched my clocks forward...

Thanks for laying it out so clearly!

It seems to me like a purely economically driven issue. An extra hour of daylight after work means people will be more likely to go out and spend money after work (particularly at retail stores & restaurants). People seldom go on spending sprees before going to work in the morning, so the daylight there is probably seen as "waste" from the viewpoint of our dominant economic paradigm.

On the non-economic front, since the world of appointments, business hours, and schedules doesn't slowly shift as the daylight increases I feel good about it being light a bit later due to DST. At this point in the winter it just feels good to have that light at dinner time. Maybe it's just my conditioning, but it feels like summer's coming!

true: noone DOes go shopping before they go to work! it's brilliant!!

but 7-11s, I don't get it? because everyone schedule is so screwed-up that they sleep in and  thus resort to 7-11 breakfasts. is that it?

is that what they're lobbying for? more tired people demanding coffee?

I think it's more like more people swinging by after work to get Slurpees and Hohos. There's a high correlation between sunlight and shopping hours, especially for consumer staples, and you're right: excluding early in the morning.

I'm with you. I *really* like to go to the grocery store first thing in the morning before my day kicks off. But I don't have kids. I imagine that mornings get a little bit crazier once you're trying to get kids off to school.