In defense of daylight saving time

In Europe this weekend is standard time weekend, when we turn our clocks back one hour to get a bit more light in the mornings. Americans do not make their clock adjustments until a week later. Which presumably makes for some awkward time adjustments for Atlantic travelers.

Common knowledge holds that daylight saving time was introduced to save electricity. If this was ever the case this argument is by now severely outdated. Only a minuscule part of our electricity consumption is used to power lights during summer evenings.

Daylight is still nice, however, and it is worth saving, or at least worth using when it is available, which is sort of the same thing. This is what daylight saving time is for. Surprisingly, a lot of people, in most polls a majority, are against this. Their reasons may vary but many seem most annoyed by the requirement that they adjust their clocks twice a year.

The power of the dark side

The fact that it is annoying to have to adjust your watch is not a particularly strong argument. And it is getting weaker and weaker as fewer and fewer people actually wear a watch. These days most things showing us the time are controlled by a computer and computers can adjust to daylight saving time all by themselves, liberating us from this arduous labor.

The main problem is not adjusting watches as much as adjusting time itself. Daylight saving time means that clocks are turned forward one hour in the spring and turned back one hour in the fall. Turning the clocks forward means that people are losing one hour of their lives. With busy modern lives and fixed schedules people have no option but to take the lost hour from their sleep accounts. 

Numerous studies have shown that in the days directly after the spring transition there are more accidents, more health problems and higher overall mortality. This seems to be wholly due to sleep deprivation. People have more traffic accidents and workplace injuries when they are tired and also more heart attacks and stress-related mental problems.

While these disadvantages are real enough the studies almost always only focus on the actual transition between standard time and daylight saving time. The eventual benefits of having different time sets for winter and summer are usually not quantified. 

However, there are obvious drawbacks with only using standard time or only using daylight saving time. For example, using daylight saving time year-round forces many people to go to work in darkness during the winter. And always using standard time makes summer nights darker with subsequent loss of quality of life. 

The few scientific studies applying a holistic perspective on daylight saving time tend to reach the conclusion that adjusting the clocks are net positive. For example this study finds that daylight saving time overall leads to fewer traffic accidents (due to better overall visibility). A Brazilian study finds that daylight saving time decreases the number of homicides (due to brighter evenings). And this study finds that daylight saving time increases children’s physical activity (in Europe and Australia at least, American children are apparently insusceptible to increased daylight).  

Let there be light

While the spring transition is annoying but manageable, there are real advantages of daylight saving time. Daylight is a finite resource and daylight saving time allows us to make the most of it, shuffling daylight from times when we do not use it to times when we need it.

Daylight saving time might seem like a modern invention, and it is, but the real modernity here is clocks and timetables. In the old agricultural society it was perfectly normal to rise earlier in the summer than in the winter. In fact, anything else would have been sheer madness since artificial light was poor and expensive and you were forced to utilize what daylight there was in order to be able to do what needed to be done.

Our modern society demands that we work according to fixed schedules. That is the only way we can cooperate in our exceedingly complex world. Adjusting schedules to take account of changes in daylight is simply not feasible. But we can adjust the clocks so that all schedules are pushed earlier in the summer and later in the winter. This is what daylight saving time does.

The principle behind it is a rather simple one. In winter, when daylight is limited, we use up all our daylight no matter what. Therefore we use standard time where noon is the middle of the day. In the summer, we have an excess of daylight, especially in the mornings because modern humans do not like to rise early. By moving clocks forward so that 13:00 is the middle of the day we take one hour of daylight from the early morning, when hardly anyone is awake, and move it to late evening when many people are still out and about.

Daylight saving time is only effective when daylight hours vary significantly between winter and summer. This goes for mid to higher latitudes, the temperate areas where richer nations tend to congregate. In tropical areas there is not much difference between seasons and in very high latitudes it is more or less dark all winter and light all summer. For these areas the cost of transitioning might not be worth the benefits of slight savings in daylight. 

When there is will there is a way

No one is seriously arguing that daylight saving time during the summer is negative in itself. The criticism is aimed at the transitions from standard time to daylight saving time. If there are negative effects of something intrinsically positive it is usually a good idea to try to mitigate the effects rather than removing everything. If there only was a way to maintain daylight saving time without the awful transitions. 

In fact, there are several ways in which the time transition may be handled. One obvious way, which was suggested already when daylight saving time was first contemplated in the early 20th century, is to split up the adjustment over several weeks. Instead of adjusting the clocks with one hour over one weekend the adjustment could be made over 3 or 4 weeks with 15-20 minutes adjustment each time.

This proposal never took off due to the inordinate amount of clock fiddling it would have required. Today, when most clocks are computer controlled, it might have been easier to pull of. If all or almost all clocks had been computer controlled it would have been possible to imperceptibly adjust the clocks with 2 minutes per day over a 30-day period to achieve the one hour adjustment without anyone noticing.

A much more simple mitigation strategy is to allow people some rest after the tiring spring transition. The transitions are always done early in the morning on Sundays, only about a day before people are forced out in the dangerous world again. This is a holdover from the times of the six-day workweek when Sunday was the only free day. Today the five-day workweek is universal and the daylight saving time transition could just as well be placed on a Saturday morning, giving people two full days of rest before returning to work.

If this is not enough it is perfectly possible to add a public holiday to the spring transition. It could be the Daylight Saving Time Friday when everyone gets the Friday off and clocks are adjusted in the early Friday morning. This way people would get three days of rest before returning to the world.

In Europe there is an even better alternative since Easter in Europe is a long holiday where both Good Friday and Easter Monday are public holidays. Doing the spring transition on Good Friday would give four days of extra sleep before returning to work. On the other hand there would be some potentially stressful family reunions in the meantime.

Saving the day

It is difficult to understand how anyone can be against an elegant solution like daylight saving time. Probably it is due to myopia. When people are faced with something that has a small but clearly stated disadvantage (like losing an hour of sleep in spring transition) and a large but undefined advantage (like gaining an hour of daylight every day for half of the year) they tend to only see the disadvantage. This is also attractive to politicians. When they see an issue with a distinct downside and a fuzzy upside they know it is time to be outraged.

Currently politicians in both America and Europe are working hard to abandon daylight saving time, or at least the twice yearly transitions. In fact, the European parliament has already decided that daylight saving time should go. Luckily there are checks and balances in the EU and the parliament’s decision is null and void until it is approved by the council of ministers, an approval that does not seem to be imminent. 

One thing holding back is the uncertainty of what will come instead. The parliament’s resolution said that countries should decide for themselves if they wanted permanent standard time or permanent daylight saving time. Which would presumably create a patchwork of different time zones all across Europe. 

The few examples of regions abolishing daylight saving time is also not encouraging. In 2015 Chile introduced permanent daylight saving time. The move was not popular and after a public outcry the biannual setting of the clocks was returned. 

Another discouraging example is Russia which abolished clock adjustments in 2011 and opted for permanent daylight saving time. As in Chile there was an outcry when the public realized just how dark winter mornings can be when forced to rise an hour earlier than usual. In 2014 Russia switched to permanent standard time instead (and people started grumbling about dark summer evenings instead). 

It is a bit ironic but the best defense for daylight saving time right now is the inability of its detractors to decide if they want permanent standard time or permanent daylight saving time. This is not only ironic but also very logical. Standard time is the best alternative during the winter and daylight saving time is the best alternative during the summer. 

Two opposing sides usually call for a compromise. And in this case the compromise solution is already there. Since standard time and daylight saving time are best suited for different times of the year it is only rational to use them both. The daylight saving time system has its drawbacks and there are definitely ways it could be improved. Abolishing the whole system is not one of them.