Spain has long been suspected to suffer from their timezone choice. I do remember reading about that problem before, and a fast Google search finds several articles discussing the issue. (For example https://www.theguardian.com/commentisfree/2017/feb/22/spania...)

Up to a certain point, countries adapt. For example, Germany and France are in the same timezone, but their schedule is shifted. This can be easily seen when looking at the TV schedules. In Germany, evening TV starts at 20:15 (the start of movies, ...). In France it's more like 21:00. When I lived there it was 20:50, but TF1 now seems to start at 21:05.

German TV: https://www.zdf.de/live-tv

French TV: https://www.programme-tv.net/programme/chaine/programme-tf1-...

Similarly, schools and kindergardens are usually not at the same time.

This local shifting works more or less, but can't be stretched too far. Especially multinational companies have expectations that workers come in at certain times. This is the problem that Spain faces. (I couldn't easily check by how much Spanish are shifted as Spanish TV schedules don't seem to coordinated like in France or Germany).

Spain is, however, thought to be 2hrs 30mins ahead of "sun" time, not a mere one hour we're talking about here.

> thought to be 2hrs 30mins ahead of "sun" time

Spain is certainly ahead by a lot, but the 2:30 is for Galicia which is the westernmost tip of Spain (which is on the same longitude as Portugal, which is in a different time Zone).

For most of Spain it’s less, tough still a lot.

Here is a great map [1] that shows how much each place is offset vs solar time.

Spain is shifted pretty far, but some places are even further offset. Large parts of Russia and China, but also Alaska and Argentina.

Also, since the OP concerns Canada, worth noting that the map shows Canada being more shifted than the US, which I didn’t expect.

[1] https://io9.gizmodo.com/how-wrong-is-your-time-zone-15285708...

Not to mention that Daylight Savings was invented during the first world war (while accurate timekeeping was invented several centuries earlier), and most of Asia and Africa do not follow it. I am incredibly skeptical of claims that Daylight Savings is the sole reason for some health effects, purely because Daylight Savings is an outlier in our history of timekeeping and is not universal today.

Is that because Africa is equatorial? Day length and Sun rise/set times don't change much over the year right?

No, Africa extends between 30 south and 30 north, roughly. Same latitude as the south of the US.

The US also has a North. Most people in the US are above 30 North, and daylight saving is pointless in the south.

The letter doesn't argue against eliminating the annual time shift, it argues for using Standard Time rather than Daylight Savings Time for the permanent time.

Is there even a meaningful difference in the long term? Starting times for school and work are not set in stone, but are different in different industries/regions, and constantly changing. If the government declared by fiat that the official clocks would jump ahead by 4 hours (thereby setting "11am" to be sunrise on June 1st, or whatever), everyone would eventually just adjust their schedules so that work started at "1pm", dinner time was about "11pm", etc.

The current daylight saving time standard, where we switch time twice a year by an hour, is not meaningless in the same way because schedules are "sticky" on sub-6-month timescales; a business keeps opening at 9am both before and after the clocks change in the Fall.

I think culture is more resistant to change than you realize. I would very much predict that for most of my lifetime, businesses will continue to open at 9am regardless of whether we decide to permanently shift the clocks forward or permanently shift them back. Nine o'clock is the number burned into people's brains.

And the rest of culture more or less follows that one start time.

Walking around a city today, I saw a bunch of different shop opening times, from 7am to 11am in half hour increments. I don't think 9am is that important.

It's actually more like two hours. In the east of CET you have Niš, Serbia, which has daylight hours of 06:08 - 16:23. In the west you have Pontevedra, Spain with daylight hours of 08:02 - 18:26. Both cities are close to the same latitude.

So I wonder if society (business, education, organizations) operates on the same schedule in Paris and Berlin? (or between Madrid and Budapest)

I suspect there's at least some adjustment, which indeed could negate health effects even if they existed (provided the operational adjustment exactly equals their time offset). OTOH If adjustment is incomplete or there's some numerical attachment (universal preference to start at specific hours), then effects could be a possibility.

Between Madrid and Budapest, definitely not. Spain still mostly has the siesta - everything closes for a few hours in the middle of the day, and plenty use it to have a snooze. This possibly mitigates the western edge of CET issue.

I live in Eastern Portugal, where there’s no siesta, but then again we’re on GMT here, which is better aligned to the sidereal day.

Germans are known to start their day earlier that the french. Getting to work before 8 is very common in Germany and it's definitely not in France.

> If the time shift has serious implications, then it ought to be possible to demonstrate them by comparing Paris and Berlin.

That only holds true in all-else-being-equal situations. Or equal enough - I don't know if you can apply this to Paris and Berlin.

There is a long-standing belief that the Spanish style of workday and meals has everything to do with being forced into the central time zone.. I'm not sure on Spain, but France seemed like a nation of sleep deprived zombies to me as a child[_].

It seems simpler to me to enforce a specific time after sunrise that all institutions must create a break for children, office workers, etc to go outside.

[_]Other children told me they copied their parents pattern, to sleep after midnight awake before 7. I think they were copying insomnia.

Edit, downvotes: So time zone implementations from documented fascists are a perfect defence of new changes because we aren't actually willing to discuss their possible negative affects on entire nations?

https://en.wikipedia.org/wiki/Time_in_Spain