[Riesling]

> because people have little control over when their day starts.

This is actually one of the best arguments for standard time all year around!

If we force people to start the day at a specific time, we have the obligation, that for as many people possible, this time will be in sync with their circadian rhythm. And this can be guaranteed best with standard time.

[cgriswald]

> If we force people to start the day at a specific time, we have the obligation, that for as many people possible, this time will be in sync with their circadian rhythm. And this can be guaranteed best with standard time.

Neither Standard Time nor Daylight Savings Time align with our circadian rhythms, because our rhythms change in response to external stimuli like the sun. The rising and setting sun varies a lot and differently depending on your latitude.

As for the obligation you propose, let's say I work for CompanyCorp. And let's say they normalize on starting work at 8:00 am Standard Time. That means Larry who lives 5 miles from CompanyCorp wakes up at 7:30 am and makes it to work on time. I live 5 miles from CompanyCorp in the other direction and because of traffic I have to wake up at 6:30 am to make it on time. So does CompanyCorp have an obligation to Larry or to me? What about Greg, who is a headbanger, and has long, luxurious locks that necessity an extra 15 minutes getting ready?

Additionally, CoffeCo has to open up to provide service for all of the commuters who work at CompanyCorp, so they open at 6:00 am to be open in time for me to get coffee before work. And, of course, the schools have to be open so parents can see off their little ones before work.

I'm frankly not sure how you do this for "as many people as possible" without just moving the time forward an hour to help everyone who isn't currently best served be served a little better.

[jasode]

>one of the best arguments for standard time all year around! [...], this time will be in sync with their circadian rhythm. And this can be guaranteed best with standard time.

To clarify because of possible imprecision around the word "standard". I think what you're saying is that circadian regularity is best achieved with "unchanging" time instead of "standard" time.

There's Standard (capital 'S') time where the high point of the sun roughly at ~12pm. And then there's Daylight Saving time where the high sun is roughly at ~1pm. A circadian rhythm can be compatible with either of those systems if it's kept the same all year long.

[Riesling]

Sorry for being imprecise, but I actually meant Standard Time (as in noon at about 12pm). Our circadian rhythms are not as flexible as many people think. There are many studies showing that people sleep less if the sun sets later, causing a net sleep loss with related health problems.

[tbabb]

> if the sun sets later

The sun sets when it sets. We are choosing what clock label to put on that moment.

Getting up an hour earlier and thinking of the same clock position as "later in the day" is exactly the same as using DST— except clock noon and solar noon won't be permanently misaligned.

[taeric]

You know solar noon is not necessarily noon. Right? Pretty sure it changes throughout the year, too. If so, that seems more an argument for dst. I'll check in a bit. Someone may just know, though.

[kgwgk]

Solar noon changes a bit through the year, but the range is just half an hour: https://www.sundials.co.uk/eot

[taeric]

Odd, this would seem to be a data point for DST being just half an hour.

That said, that chart is suspicious for not having jumps for DST. How does that work?

[kgwgk]

DST doesn’t have anything to do with the oscillation of the true noon at any location by +/-15 minutes around the year (that cycle is not even summer/winter).