The Moderation Conversation, Email Edition: Standard Time vs. Daylight Savings

This is the second installment of “The Moderation Conversation, Email Edition”, a spin-off of RM’s “Moderation Conversation” feature.  The topic this time was something that seems inconsequential but has inspired one of our most adamant disagreements in ages: is Daylight Savings Time better than Standard Time or vice-versa? 


Matt, I’m feeling a bit down at the moment and I need your help.  I’m writing this to you on October 30, which means we only have three days left until Daylight Savings Time ends.

For me, this is perhaps the worst time of the year, at least outside of the cold doldrums of February.  The end of Daylight Savings Time means that it will start to get dark around 4:30pm from now through March.  This is terrible!  Two weeks ago, we were enjoying warm, breezy fall days, but by next week, it will be cold and completely dark by the time I leave my office each afternoon.

I love Daylight Savings Time.  I’d endorse a petition to make it the year-round standard in a heartbeat.  What’s the point of changing clocks twice a year?  What’s the benefit of manipulating time such that evening falls before most people clock out for the day?  I’d rather grab an extra hour of sun in the afternoon than an extra hour in the morning, when I’m barely conscious enough to hate the morning traffic, let alone appreciate the beauty of fresh light.

Word on the street is that you actually prefer Standard Time to Daylight Savings Time.  I find this unfathomable and I’m inclined to completely, vehemently disagree, but I’d like to hear: what’s your rationale?  Can you help convince me that there’s value in adopting Standard Time?


Chris, I’m sorry to hear that you’re feeling down, but I do think I might be able to help. What if I told you that getting rid of Daylight Savings Time might literally make all of us a little bit happier?

Before I explain why, I want to point out that one alleged benefit of DST is greatly oversold. The primary motivation for instituting DST was the belief that it would conserve energy by reducing the need for artificial lighting on summer evenings. This argument dates back at least to the time of Benjamin Franklin, who thought that people would burn fewer candles if everyone agreed to wake up and go to sleep earlier during the summer. It was also invoked by Congress as a reason for lengthening DST starting in 2007.

Unfortunately, there’s scant evidence that DST actually saves energy, and some reason to think that it actually has the opposite effect. In a 2008 National Bureau of Economic Research working paper, economists Matthew Kotchen and Laura Grant analyze the impact of an Indiana law that required all counties in the state to adhere to DST, many of which had not done so previously. By comparing patterns of energy usage in those counties that had practiced DST before the passage of the law to those that had not, Kotchen and Grant were able to isolate the effect of the time shift on electricity consumption.

Their results show that DST may paradoxically increase the amount of electricity used, perhaps because any savings realized from the “Benjamin Franklin effect” are swamped by an increased reliance on air conditioners or fans (since more sunlight in the evenings also means that the evenings will tend to be warmer). The increase is not enormous – Kotchen and Grant estimate it at a few percentage points – but at the very least it calls into question the main rationale for DST.

But why would I say that year-round Standard Time has the potential to make us happier? Well, science has shown that exposure to bright light in the morning is mood-enhancing, and therapy involving “light boxes” is sometimes used as a treatment for depression. Such therapy is most effective for individuals who suffer from the aptly acronym-ed Seasonal Affective Disorder (SAD), a form of depression that strikes mainly during the winter months.

Although patients with SAD generally start to feel worse in the late autumn and better in the springtime, some clinicians report that they struggle with the start of DST (when the mornings suddenly become darker) and experience the return to Standard Time as a kind of reprieve (when the mornings become brighter).

Even for those of us who don’t have to deal with SAD, the “spring forward” can still have deleterious consequences for our health. In addition to its effects on mood, there are studies suggesting that heart attacks and suicides also spike around that time of year.

I agree with you that changing the clocks twice a year is pointless – so let’s stick with Standard Time all year long!


I appreciate your efforts to convince me why Standard Time should usurp Daylight Savings Time all year round.  Unfortunately, I’m having a hard time buying your arguments; even in tandem, they’re not persuasive enough to make me think that darkness at 4:30pm is a worthwhile trade-off.

I’ll readily accept the energy statistics you cite, but by your own evidence, it does not seem like Standard Time has an overwhelming advantage over DST with respect to electricity conservation.  It also sounds like the worst cases of Seasonal Affective Disorder occur during the heart of the winter when Standard Time is most acute and days are shortest.  And the instances you report regarding heart attacks and suicides imply causation with DST when only correlation may exist.  On the whole, all three points strike me as insufficient to justify a full year of Standard Time.

But there are distinct advantages to a full year of DST.  Joe Stromberg at Vox notes how a full year of DST would allow for extra time after work for leisure activities, including shopping, which is why retail sales rise a little bit during the summer.  It’s not a huge increase, but hey, it’s something.  He also reports that DST is correlated with reduced instances of robberies due to the extra light at night.

Benefits for school children are perhaps even greater.  Additional light in the afternoon would allow for more time spent in after-school activities, particularly exercise.  Interestingly, the National Parent Teacher Association has been a key opponent of expanding Daylight Savings Time in the past, arguing that light in the morning is necessary when children are traveling to school.  But this is easily solved by pushing back the start times for school, which is long overdue anyway (and perhaps a topic we could discuss in the future).

More important, though, are the lives that would be saved by full-year DST.  From Time (no pun intended): “Adding an hour of sunlight in the evening year-round would save the lives of more than 170 pedestrians annually, according to a 2004 study in Accident Analysis and Prevention. ”  Says Steve Calandrio, a professor who has studied the effectiveness of DST policies: “At 5 pm virtually everyone in society is awake.  There are far more people asleep at 7 in the morning than at 7 in the evening.”  It’s as simple as that.

Seems like there are benefits to both a full year of Standard Time and a full year of Daylight Savings Time, but the upside to 365 days of DST far outweighs that of ST.  What say you?


I admit that the research showing a link between the start of DST and heart attacks does not prove causality – it can never be repeated often enough that correlation does not imply causation! – but neither does the study you refer to which claims that DST reduces crime. That said, the evidence is pretty suggestive in both cases, so maybe we both need to acknowledge that our favored regime comes with costs and benefits.

I’m a little confused about the points one of the articles you link to makes regarding DST’s effect on retail sales. The article quotes Michael Downing, the author of a book called Spring Forward: The Annual Madness of Daylight Saving Time, as saying that “[t]he barbeque grill and charcoal industries say they gain $200 million in sales with an extra month of daylight saving—and they were among the biggest lobbies in favor of extending DST from six to seven months in 1986.” Downing also mentions the golf equipment industry, the fuel industry, and the “Hearth, Patio, and Barbecue Association” as advocates of that move.

What do these industries have in common? They all produce goods or services that are people are most likely to consume during the spring or summer. In other words, I can understand why extending DST to cover more of the times when people might be golfing or grilling or driving to the beach would benefit golf club makers or charcoal sellers or oil companies, but now that DST already runs from March to October I doubt that any further economic benefits could be reaped by making it year-round. I imagine that not very many people golf in the depths of winter (although I did see some mini-golfing going down earlier today, and it’s almost the end of November).

I wonder how you might feel about the following compromise, which would both address my concerns about rousing people while it’s dark outside and still grant you your cherished evening sunlight: shorten the workweek so that we can all awaken at the same time we do now and have time to frolic in the natural light after we come home. You might be familiar with the argument made by some economists that a shorter workweek would distribute paid employment more equitably across the population and simultaneously reduce both joblessness and overwork. I can’t say whether anyone has ever argued for such a proposal on the grounds that it would give us more evening sunlight, but it sure seems like that would be one of the consequences. I’d love to get your thoughts!


Agreed with you that it’s important to acknowledge our favored regimes both come with costs and benefits.  Though I still believe all-year Daylight Savings Time is preferable to the status quo, the arguments and information you’ve brought up against DST are definitely helping me look at the bright side of things.  (Pun sort-of intended.)

As you note, the sales benefits of DST are almost certainly a bit overblown, especially since only a select number of retailers are actually reaping the rewards.  But I still think the arguments I cited about children benefiting from light after school, coupled with research that suggests a causal relationship between Standard Time and pedestrian deaths, tip the scales slightly in favor of full-year DST.

Your compromise proposal about a shorter workweek is fascinating, albeit a few hundred orders of magnitude more difficult to institute than passing a law to mandate year-long DST. But it’s true!  If everyone is working fewer hours, there will most definitely be more time to enjoy the sunlight during short winter days.  Perhaps this will be a byproduct of the basic income policy Bernie Sanders is sure to institute when he wins the 2016 presidential election.  Only two more years!



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