Savings at What Cost?

Daylight saving time – that semiannual ritual – is an active source of debate and even legislation. In the United States, some are pushing for the adoption of permanent daylight saving time.

This move has drawn much criticism from science, as well as people worried about their sleep – like many of us!

Benefits of daylight saving

On one the hand, the springtime switch of moving 1 hour ahead provides an extra hour of daylight during the warmer months, after work hours. This can brighten the moods and physical activity levels of those who are normally trapped in an office and those who enjoy being outdoors.

On the other hand, changes in the light sometimes cause anxiety in those who don't sleep well anyway, as they worry it will affect the little sleep they do get.

What are the costs of time change?

It can be argued that an hour or so of jet lag has similar effects on social activity when we travel. But whole populations do not suddenly travel en masse across multiple time zones.

Even migrant or "fleeing" populations do not travel all at once by plane to a new time zone – they generally are walking or driving and adapt as they go. This kind of sudden adaptation with shifts in the clock in the springtime happens to millions of people at the same time and across much of the world. So its impacts are more readily studied.

How does daylight saving time impact health?

Unfortunately, the switch to daylight saving time is associated with major public health problems.¹

The American Academy of Sleep Medicine (AASM) and its equivalents around the world take public positions on these matters. The AASM's position statement on daylight saving time advises against switching away from "Standard Time 1" for a variety of reasons.

Daylight saving time is less well aligned with our natural biology. It affects our entire body's circadian rhythms, including that of our sleep.¹

Some studies have shown a link between daylight saving shifts and:^1-4

• Accidents, particularly motor vehicle accidents
• Cardiac problems
• Mood disorders

Because of the public health impacts, the AASM advocates for remaining on standard time year-round, or some fixed national standard time.¹

And they are not alone. The Sleep Society, the Society for Study of Biological Rhythms (an international organization), and numerous others advocate for a permanent standard time as well.^5,6

My personal preferences and why

I personally love the light of summer. I'm an "early bird" – a real lark. In high summer here in the UK, it is only really dark from 11 PM to about 4 AM. However, it would be light for long hours even without daylight saving time. Perhaps people in lower latitudes would notice the switch and its beneficial effects more than those in higher latitudes.

So, I get to benefit from both early mornings as well as longer days in the summer at my higher latitude here in the UK. But I find the switch back to standard time in the autumn very difficult. I find myself in a sudden low mood, thinking about eating dinner at 4 pm and bed at 6 pm! In the depth of winter, it's dark when kids are out of school at 3:30 to 4 pm and dark until 8:30 am.

Time switch and the social jet lag

Life feels very cut short, and it's much more disruptive for me than the springtime switch. Now it would be dark anyway, and only about an hour's difference on both sides – but it's the switch, and it's social jet lag that feels all the more problematic for me.

Although I love, love, love the switch in the spring, given its public health impacts (and also my personal hate of the switch back), I'm all for staying on standard time.

Do you think you would prefer staying on standard time, or do you prefer the switch to daylight saving time? Does it affect your insomnia? I would be curious to know and to see the variety in our community's own "position statement!"