Yet another Hacker News

Permanent Daylight Saving Time Could Harm Sleep and Mental Health, Analysis Says

34 points throw0101a 1 hour ago 79 comments

throw0101a 1 hour ago | parent

Open-access link to the study in the Canadian Medical Association Journal:

> In this analysis, we focus not on whether seasonal clock adjustments should end, but on which policy should be adopted if time changes are eliminated. We explore the public health implications of pDST and pST — with attention to mental health and broader determinants of health — and propose measures to monitor and mitigate the impacts of policy change on population health.

* https://www.cmaj.ca/content/198/34/E1335 / https://doi.org/10.1503/cmaj.261089

* PDF: https://www.cmaj.ca/content/cmaj/198/34/E1335.full.pdf

swader999 1 hour ago | parent

Anyone looking at this with an ounce of willingness to research it would have chosen permanent standard time but they never even offered that in any of the referendums across the provinces that switched. I'm getting the high end bright wake uplights for my kids this winter. Pretty annoying.

rolosa 1 hour ago | parent

People don't even know if it's currently daylight savings time or not, and I certainly don't. All I care about is whether or not I need to change the hours. And I think most people care about that too. They don't really care about the label. They just don't wanna have to change the time every year.

opan 1 hour ago | parent

100% agreed. Stick to either. Stop changing it.

lfuller 1 hour ago | parent

This doesn't really match my experience living in Canada. Most people I speak to in the winter are most concerned about losing an hour of daylight in the evenings - the immediate darkness after work is obvious after the change.

KoolKat23 1 hour ago | parent

It depends where you live. In Ireland it makes a world of difference if the sun sets before 5pm or 6pm.

Staying on Summer time means additional sun after work for an extra month. Can go for a walk or do something outside in the sun.

And for those further South it doesn't matter anyway.

I'd like to see what the additional vitamin D from that extra sun does to sleep etc. I imagine that's not part of the study.

monegator 1 hour ago | parent

and not only in ireland.

It is so depressing to wake up, go to work in the dark and go home in the dark.

seanalltogether 1 hour ago | parent

I live in Ireland too, and I would hate permanent DST in the winter. I have to get my kids to school in the morning and the sun is just barely rising in the winter months by the time I drop them off. If I had to wake them and drop them to school in the pitch black I would lose my mind.

KoolKat23 57 minutes ago | parent

By the time it's winter it's dark in the morning regardless of DST. Still can be a pain in Autumn I'm sure, the cold wet mornings for me are tough regardless.

The age old morning people versus evening people. Sounds like the kids aren't morning people either.

bfmalky 30 minutes ago | parent

It is dark, but it is starting to get light. If it isn't even going to start getting light for another hour after you leave the house you might as well be getting up in the middle of the night. It would be horrible.

KoolKat23 4 minutes ago | parent

This is the existing graph for Dublin. Sadly it already feels like that to me waking up in winter regardless. You can see the Twilight phase is much less prominent in the mornings.

https://cdn.worlddata.info/graphs/sunshine/ireland-m2.png

https://www.worlddata.info/europe/ireland/sunset.php

bryanlarsen 4 minutes ago | parent

Young kids are often morning people, but teenagers biologically have something going on that makes them almost universally not morning people. Forcing teenagers to go to school in the dark for several months of the year can make it very difficult for them to get to school, and leave them half asleep during school. This will have an impact on their grades, which can have a follow-on impact on their whole life.

We should probably start high school later in the morning even if we stay on standard time ; it's way more important if we switch to permanent daylight time.

KoolKat23 54 seconds ago | parent

What makes no sense to me, is that secondary school starts earlier than primary school? Or am I out of touch.

gib444 55 minutes ago | parent

> People don't even know if it's currently daylight savings time or not,

Can't blame em: Daylight Saving is a terrible name for something that happens during the time of year when there's more daylight

blackcatsec 1 hour ago | parent

Nobody wants permanent standard time. People want later daylight hours in the evening. All of the science behind it be damned.

mohamedkoubaa 1 hour ago | parent

I want permanent standard time

torstenvl 1 hour ago | parent

All of the science supports permanent daylight time.

Even this article, while stating the opposite conclusion, directly scientifically supports permanent daylight time as beneficial for most people.

It points out sunrise being at 0751 versus 0851 for Toronto. That's the anticipated sunrise time on 1 January 2027. The anticipated sunset time is 1651.

That means that someone working in a cubicle for a standard 0800-1700 schedule will get 9 minutes of possible daylight under winter time, versus 51 minutes under daylight time (sunrise 0851, sunset 1751).

Lack of sunlight leads to terrible circadian rhythms. There is absolutely zero scientific support for the proposition that nine minutes of daylight is healthier for our circadian rhythms than fifty-one minutes of daylight. No person could possibly argue such a thing in good faith.

(Also, I have a terminology quibble with "Standard Time," since Daylight Time is the actual standard, and we observe it eight months of the year.)

rob74 1 hour ago | parent

You can have (almost) permanent daylight time - you just have to relocate regularly between (let's say) Iceland and the southern tip of South America. Or even further north/south for even more daylight (albeit even lower temperatures).

iamnothere 54 minutes ago | parent

Why is that the “standard” work schedule? Isn’t that the problem, not the fact that noon happens at noon?

torstenvl 46 minutes ago | parent

I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.

What possible meaning could the phrase "noon happens at noon" have? That's tautological and meaningless.

And if your solution requires a wholly independent, newly built mass coordination mechanism rather than just a minor tweak to the existing one, then I think the burden you bear for arguing your position is extremely high.

iamnothere 40 minutes ago | parent

What do you think it means? I think you’re feigning ignorance.

If we’re going to ignore the position of the sun, let’s just set a single “American time” to follow DC like China does and be done with it.

torstenvl 26 minutes ago | parent

My post did not ignore the position of the sun. Indeed, it's governed by it.

I am not interested in whatever you've got going on right now. Being dishonest about others' positions is bizarre. Refusing to clarify your own is bizarre. Let me know when you're willing to engage in good faith.

iamnothere 24 minutes ago | parent

Funny since you’re the one who isn’t engaging in good faith. Judging by votes I received, I think others understand what I mean.

freehorse 46 minutes ago | parent

If the work schedule should change, that can be done in either case of the time adopted and the debate would not matter. But with the current schedule, daylight time savings makes much more sense. Where I live in deep winter you just don't see any light at all if you work a normal schedule. If there was daylight savings in the winter instead, you could at least get some light after work.

iamnothere 42 minutes ago | parent

Right, so let’s change expectations for what a “normal” schedule should be. Perhaps stock market, banking, school, and government hours could change and this would be enough to move everyone else.

bryanlarsen 38 minutes ago | parent

The studies are saying it is more important for you to get that limited daylight before work rather than after. It's much better for kids sleep and school for them to walk to school in the daylight.

rascul 21 minutes ago | parent

Noon doesn't actually happen at noon

iamnothere 18 minutes ago | parent

It’s close enough to solar noon in most places under standard time.

bfmalky 20 minutes ago | parent

It is completely ridiculous to say that someone working 9-5 doesn't see any daylight during that period. Go for a walk at lunch time.

Conversely, getting up in the pitch dark and leaving the house in the pitch dark when the sun isn't going to rise for another hour is a horrible prospect and I hope I never have that inflicted on me. The evidence in the article is clear: our bodies need light in the morning more than we need it in the evening. Yes, winter sucks in northern latitudes, but we've just got to make use of the little daylight as best as we can. The flip side is by using DST we get these lovely long evenings in the summer.

throwaway270925 16 minutes ago | parent

> Go for a walk at lunch time.

Quite the entitled, unreflected comment. Not everyone works in an office or somewhere where this is a possibility!

bfmalky 9 minutes ago | parent

Yeah, ok. If you are working on an airplane, or a submarine this doesn't apply.

alwyn 1 hour ago | parent

Based on what exactly?!

Vaslo 1 hour ago | parent

“Nobody”

My entire household wants it.

sdevonoes 55 minutes ago | parent

Just curious. Do you prefer then daylight during early morning rather then in the afternoon?

It’s interesting for me because early morning means for me: dealing with duties (prepare for school, commute to work, etc) so I don’t really mind doing that in the dark. But afternoon time means for me: free time (school/work is finished ) So if there’s daylight I can decide to go to the park, or play outside, or go to a terrace to eat something. Doing that in the dark is just not feasible

PowerElectronix 58 minutes ago | parent

Both are the same. You either change the clock twice a year or you don't. Society will adapt to it either way.

With standard time you eat at 12 and with daylight saving you eat at 1, either way you eat when the sun is highest or around that time.

The thing is that the biannual dance of the clock hands wrecks any notion of time and schedules as this month you eat/wake up/leave work too early and the next too late.

iamnothere 56 minutes ago | parent

If we’re going to adopt unnatural time standards to manipulate people, like permanent DST, let’s at least do something interesting like China does and set the whole country to one time zone. At least that way we can all ignore the “official” time and set business hours to whatever works best.

dxdm 37 minutes ago | parent

Seems relevant: https://qntm.org/abolish

iamnothere 25 minutes ago | parent

Humorous, but why is this person “calling” someone in 2026?

Anyway, China manages somehow. I obviously think keeping our time zones and moving them to standard time (noon ~= actual noon) would be best, I was just offering a farcical alternative that would be better than permanent DST.

throwaway270925 25 minutes ago | parent

Not really, as its a pretty shallow and trite article about abolishing ALL time zones around the world, not just within a country, totally different thing

inanutshellus 1 hour ago | parent

Confoundingly, not having permanent daylight savings time could harm sleep and mental health, @inanutshellus says.

If it benefits you to have DST timing, you'll want permanent DST. If it benefits you to ditch it, you'll want to ditch it.

The effects of being on the "wrong side" affect mental health and safety.

Thus... whichever way you want to be true, is true.

pixl97 1 hour ago | parent

It turns out that humans evolved in hyper local environments and are not designed to serve the needs of corporations and schedules.

christophilus 1 hour ago | parent

Yeah. I think we need to get back to a life that revolves around natural cycles and healthy circadian rhythms. It’s stupid that I have to get up in the dark to take my kid to school. Unquestionably, my kid should be sleeping until the light naturally wakes her.

inanutshellus 45 minutes ago | parent

You are on the other side of the line, that's all.

No matter which way the government goes, someone's "mental health and safety" WILL be affected... just... somewhere else.

Implying only one side has those effects (like this topic's headline) is underhanded.

GJim 1 hour ago | parent

STOP.

Discussions on daylight savings time are pointless without stating your lattitude.

[Here in London at 51 Deg North, DST is much more relevent and appreciated when the summer sun rises so early, and the winter sun so late; it helps keep ones body somewhat in line with nature].

ls65536 1 hour ago | parent

In this case, the analysis focuses on Canada, which does have a few population centres around the same latitude as London.

tonfa 1 hour ago | parent

It's all relative to how much shifted you are to the solar time anyway.

Large areas in Europe are permanently away from solar time already (regardless of DST).

jp_nc 1 hour ago | parent

Not only that but east-west position in the time zone. That’s the problem with DST… those on the west side of a time zone are going to work and school in complete darkness. We’ve tried this before and it was a disaster.

aragilar 37 minutes ago | parent

You can have smaller timezones.

david-gpu 1 hour ago | parent

I used to live in Spain, about one time zone West of Greenwich, but the actual time was set one hour East of Greenwich. A two hour difference.

That is to say, in winter we would wake up in pitch black darkness, commute in the dark, and the sun would finally rise while we were at school. It sucked. When I moved to London I was shocked to see how bright it was in the mornings because of that, even in winter.

sdevonoes 53 minutes ago | parent

> in winter we would wake up in pitch black darkness, commute in the dark, and the sun would finally rise while we were at school. It sucked.

But you had that extra daylight time in the afternoon (which in London wouldn’t be the case). Wasnt that better? Just curious. For me it would be

david-gpu 49 minutes ago | parent

No, it was not better. Waking up in pitch black darkness messes up your circadian rhythm. Just as the linked article says. Speaking from experience!

Kwpolska 56 minutes ago | parent

Latitude is only half the picture, when someone wakes up and how they spend their days also matters. I was really unhappy with DST when I had to wake up at an ungodly hour to school in the dark most of the year (except for the few days/weeks in March before the clock change).

Nursie 15 minutes ago | parent

Lived in London for 10 years.

Would have taken permanent BST in a heartbeat.

julbaxter 5 minutes ago | parent

And your longitude as well. Being at the extreme east or extreme west of your timezone is a very different experience.

Jedd 1 hour ago | parent

The _other_ option is to shift, perhaps in two x half-hour stages over a month or longer, but around the equinoxes - the 'standard operating hours' for services and businesses.

This is often overlooked as an alternative to shifting everyone's timepiece at the same instant -- I've never understood why there's so much much emotion and/or inertia around clock changes.

ang_cire 1 hour ago | parent

I'd much prefer this option; businesses open an hour after sunrise, close an hour before sunset. That's more natural and human, to actually follow nature's cues.

But you know, why inconvenience social constructs for wealth generation when you can just literally inconvenience every human alive instead?

shaftoe 1 hour ago | parent

Can we just stop changing the clock?

mrngld 50 minutes ago | parent

Most of the comments so far are pushing or pulling the clock in whatever direction their personal preference is. Call me crazy but the time should be a constant, unchanging reference.

If it's dark in your location earlier in the evening, don't mess with the clock. Agree as a local society that instead of working 800 to 1700 at some point in the calendar most people transition to 700 to 1600, if that's a local issue.

Edit: Or negotiate that with your boss. Most of my team works 8 to 5, I work 7 to 4, as long as its consistent no one cares. Obviously retail employees can't do that, but customer-facing people are working past dark no matter what if it's an afternoon shift.

brody_hamer 1 hour ago | parent

I don’t get it. Every time-change feels like such a huge relief to me.

In the fall, it means brighter mornings, making getting up so much easier for the entire family. It’s worth giving up the evening light so we’re not waiting for the morning schoolbus in the dark.

And likewise; I don’t want it to be sunny at 4am in June.

So changing the clock suits me perfectly.

For context: I’m at 45latitude (Toronto)

Ekaros 1 hour ago | parent

I never really understood why not just shift schedule. Set a certain date and move all schedules of public institutions. Inform this early enough to allow rest who want to follow. Then later fix as needed.

I fully support permanently moving to correct time. Meaning not summer time. And then just fixing schedules as needed.

oliwary 59 minutes ago | parent

I agree. There is no reason we have to be at work 9-5 or eat dinner at 7, it's just convention.

In fact, I have considered whether it may not make sense to just have a single timezone. Would make planning internationally much easier.

ls65536 41 minutes ago | parent

> just have a single timezone

We already have UTC, which is almost always used as the legal basis for all local timezone definitions. In many industries (such as in many aviation and maritime operations), UTC is used almost exclusively to synchronize things worldwide and to avoid any local timezone confusion that might cause problems.

So using UTC works great in situations where participants span multiple timezones. But I think the intuition of maintaining a local clock for local things, with solar noon kept somewhere approximately around clock noon, is still useful, since many day-to-day scheduling concerns remain entirely within one's local timezone. The key is that participants must be aware of their local timezone's offset from UTC. Not having to change their clocks twice a year would hopefully also make this easier.

dmortin 50 minutes ago | parent

But then you are the same place. You don't change the clock, but you change the schedule, so, the time is the same, but, for example, schedule starts at 7am instead of 8am. People have to get up an hour earlier.

You can't have a fixed schedule, because the time of daylight changes during the year.

aragilar 39 minutes ago | parent

Exactly, time zones exist (and have always existed, they only appeared once you needed to coordinate time across different places) as a coordination mechanism. Who and what you need to align with (e.g. where you sit on the international date line, your latitude and longitude for the solar phase) is the important part, not the actual number that appears on the clock (or on someone else's clock for that matter).

glimshe 1 hour ago | parent

I want permanent standard time. Few people seem to prefer that, although it is apparently popular in some states not well represented online.

christophilus 57 minutes ago | parent

How about, pick a time and stick with it. Then, if it turns out people should be getting up with the sun, we change the stupid school and business hours to accommodate humans?

PowerElectronix 56 minutes ago | parent

Permanent whatever time is better than changing times. Standard or daylight saving doesn't matter, society will adapt schedules to either.

einarfd 51 minutes ago | parent

I couldn't see anything in the article about early vs late risers. My impression when looking at this kind of research, is that it, like everything else around this subject in society. Is from the perspective. That early risers are the only valid type, and us late risers are anomolies, that should not be catered to, and our challenges are a moral failing.

For me living in Norway, one of the hardest things every fall, and that makes me depressed for weeks, is when one weekend, when the days are already getting shorter fast. One hour of evening day light gets janked overnight. It is imo. horrible.

skerit 31 minutes ago | parent

> one of the hardest things every fall, and that makes me depressed for weeks, is when one weekend, when the days are already getting shorter fast. One hour of evening day light gets janked overnight

Same! Though you have it way worse.

I live in Belgium, I mostly get up around 08:00/08:30. I already feel quite guilty for not making the best of use of daylight in spring and summer. Around the summer solstice, the sun comes up around 05:30 over here. I can't imagine it coming up at 04:30 in the middle of summer. (Which is probably already what happens in Norway?)

lennoff 50 minutes ago | parent

Can't we settle somewhere in the middle? Like occasionally sleeping an hour longer, but never shorter?

kator 49 minutes ago | parent

I would rather the planet run on UTC time and no "savings" time stuff either. It would take a while to get used to, but it would make working with my teammates across the world easier, the constant time zone conversion, oh are they on DST, oh they don't honor it.. way more exhausting than hours of light or dark on one side of my work day or another.

ang_cire 46 minutes ago | parent

This is all a product of decoupling hours of operation from seasonal cycles.

People are worried about waking up in darkness to have to go to work (rightfully), and the actual solution is not to shift the clock around, it's to shift starting hours later in the day, and end working earlier, in the winter.

We're arranging our entire lives around the convenience of corporations, and doing studies to figure out which way of doing so is least detrimental to us, rather than just not doing so in the first place.

aragilar 35 minutes ago | parent

That is exactly the same as timezones, except uncoordinated, so even more of a mess.

drxzcl 30 minutes ago | parent

No it's not! Under this proposal you work shorter days in winter, longer days in summer, to match the natural light.

aragilar 19 minutes ago | parent

Except you're not going to be more productive working those additional hours in the summer, so as unless you're willing to take the respective pay cut for working less hours, this proposal is a non-starter. Personally, I'd argue that more (smaller e.g. 15 minute) shifts would be better (and you could more closely track sunrise), and avoid the hard shift which it feels is the main complaint people have with switching timezone.

ang_cire 5 minutes ago | parent

It's a non-starter in your mind, because you have already accepted that businesses get to dictate it be so, and that instead we must pass laws (e.g. daylight savings) to govern all people to conform to their wishes.

We can also let people dictate that it will be my/another way, and pass laws to govern businesses instead.

And it's wild that so many people don't seem to realize this is perfectly normal and expected, nowadays.

Did you know we didn't used to have 5-day workweeks? Or 8 hour days as the norm? Or worker's comp? etc etc etc etc...

tobr 29 minutes ago | parent

Read ang_cire’s comment again. It is describing shifting hours around across the year, or reducing them, not shifting them around across the day.

JonChesterfield 44 minutes ago | parent

At a minimum we could do it on the same day in the UK as in America. All the meetings moving by an hour four times a year is deeply unhelpful. I have no idea when the clocks change but I definitely missed a lot of meetings by an hour.

skerit 42 minutes ago | parent

> The health evidence points to standard time, largely because morning light matters for our body clocks, sleep, and mood

Depending on where you live, depending on how long your commute is and by what time you have to be at your job, ... a lot of people don't get that anyway in the winter. There is no one solution, and you're going to piss of a bunch of people anyway.