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The rationale for daylight savings in a southern latitude like California is this: People generally wake up, and go to work the first thing in the morning. The
by henrikschroder 8y ago
The rationale for daylight savings in a southern latitude like California is this:
People generally wake up, and go to work the first thing in the morning. They would like to travel to work after sunrise. They would also like to maximize the amount of daylight they get to enjoy outside of work.
This means that in the summer, all the daylight before waking up is "wasted" so you want to move solar noon forward. But if you move it too far, it'll be pitch black when people get to work in the winter, which is why you then have daylight savings to move solar noon back a bit.
If you live further south, like Hawaii, the difference in length of day between winter and summer is very small, so you can't shift solar noon around. Therefore, Hawaii doesn't do daylight savings.
If you live further north, like Sweden, the difference in length of day between winter and summer is enormous, and in the summer the sun rises at like 3 in the morning with daylight savings, and in the winter the sun rises at 10 with standard time, and the rate of daylight change around the equinoxes is huge, so the effect only lasts a week or two. It makes absolutely no sense to have daylight savings there, and the EU parliament making it not mandatory for countries is a step in the right direction, i.e. abolish the useless thing in Sweden.
Spain and the other Mediterranean countries could maybe keep it for all I care, but Spain has a weirdly skewed solar noon anyway...
- paulsutter 8y agoSince it’s getting dark earlier after work, how does this maximize daylight outside of work? > They would like to travel to work after sunrise. They would also like to maximize the amount of daylight they get to enjoy outside of work.
- function_seven 8y agoWell the seasons don't give us much wiggle room here, so the thinking is to (1) make sure the sun has risen when you set off for work. If there's extra sunlight still, then (2) let's have that after work. In the winter, you can't have both, so you pick #1. In the summer, you have "extra" sunlight that's being wasted on the sleeping, so you shift it to after work and get #1 and #2.
- henrikschroder 8y agoHere's a pretty good graph that illustrates the concept: https://www.timeanddate.com/sun/usa/san-francisco https://www.timeanddate.com/sun/usa/san-francisco DST ensure that sunrise is kept at around 6 in the morning, this removes the "waste" of daylight from before most people wake up, and moves it to after work hours in the summer. Here's the same graph for Stockholm: https://www.timeanddate.com/sun/sweden/stockholm https://www.timeanddate.com/sun/sweden/stockholm There's not enough daylight in the winter to cover an entire working day and more, and there's too much daylight in the summer so everyone will "waste" it by sleeping, which makes DST pretty much useless. Edit: Here's Honolulu for reference: https://www.timeanddate.com/sun/usa/honolulu https://www.timeanddate.com/sun/usa/honolulu The band of daylight is almost the same width over the year, so moving it up and down doesn't do anything for people.
- ants_a 8y agoI live in the same latitude as Stockholm, and the extra hour of daylight in the afternoon is still nice in the summer, while having the sun rise one hour earlier would be more an annoyance than a benefit. We tried that, it was definitely not an improvement. I wouldn't actually mind keeping daylight savings time the whole year to reduce the time of the year when it's pitch black outside at all non-business hours.
- lultimouomo 8y agoLiving in Italy I get the feeling that people are overwhelmingly in favor of DST; I know I am. I think the big screw up from EU was that after the poll (to which pretty much only Germans answered) they just said they would remove DST altogether instead of recognizing that different geographical regions have different needs. They just wanted a no-cost change to say "see? we listen to people"; but pretty much everyone in southern Europe heard "see? Germans decide for everyone!", and nationalists party marched on it. From the article it looks like they backtracked on it and they'll allow countries to choose to keep changing time twice a year; I sure hope so.
- lagadu 8y ago> Spain has a weirdly skewed solar noon anyway... That's because they're mostly in the wrong timezone, they should be on Western European time like the UK and Portugal. Interestingly enough the reason for that is Hitler :)
- blattimwind 8y ago> "see? Germans decide for everyone!"
- magduf 8y agoNot exactly. The reason is themselves. They chose to have a dictator, and that dictator changed the timezone to match Hitler-time way back in the 1940s. Then they just never changed it back, even though their dictator finally died over 40 years ago. So they've made conscious choices to stay in the wrong timezone for almost 80 years now.
- mac01021 8y agoBut can't we just leave the clocks unchanged and then let people wake up at sunrise and go to work and school as early as they like?