3 ms·

I responded in that fashion to mimic the OP's tone. --- The fact that daylight saving time is an approximation for fixing sunrise to a specific time is common

• romwell 8y ago
  Thank you for answering. Now let's discuss this answer. The first question is: which specific time? This time will differ based on the timezone and geography. Because of timezones, sunrise time effectively makes a one-hour jump at the transition points, which makes this chart of yours look different for people living living close to timezone border vs. someone living in the center. To that end, which time zone and which city was this chart made for? Because we'd need many charts like that to see the effect of DST on sunrise time. (Remember, timezones make sunrise/sunset times depend on longtitude (exact coordinates, actually) as well as latitude and time of year!). Thankfully, some people have done just that[1][2] (note that [2] is interactive!). As you can see by playing with [2], if your goal is to have sunrise before 7:00AM across the country on as many days as possible, then DST works against this goal. Of course, one can always throw one's hands up in the air and say "it's an approximation". In the same sense, 0 is an approximation to any number -- just not a very good one. The US foreign debt is approximately 0 dollars, if you don't talk about error margins. Now, looking at the interactive chart at [2], do you really think that DST is a better approximation to "having the sun up at (your chosen time)" than doing nothing at all? Or shifting the whole timezone by an hour? [1]http://mentalfloss.com/article/71521/heres-how-daylight-saving-time-affects-your-part-country http://mentalfloss.com/article/71521/heres-how-daylight-savi... [2]http://andywoodruff.com/blog/where-to-hate-daylight-saving-time-and-where-to-love-it/ http://andywoodruff.com/blog/where-to-hate-daylight-saving-t...
  • goflyapig 8y ago
    > The first question is: which specific time? This time will differ based on the timezone and geography. That's not what it's about. The specific time is irrelevant - that's just an arbitrary number. The reasoning in the blog posts you link to is just based around making comparisons to another arbitrary number (7 AM). Rather, the point is shape of the curve. DST makes the sunrise time approximate a constant line. In other words, if you plotted the time difference between sunrise and "x o'clock" (for any x) for every day across the year, DST reduces the standard deviation of those values. The argument is that circadian rhythm causes humans to naturally wake up near sunrise. Most people also wake up at some fixed time in order to start their workday (because businesses generally have fixed hours, and people wake up just before going to work). DST makes it so that the difference between this fixed time and 'sunrise' can be minimized over the year. Without DST, you will not be able to have a fixed wake-up time and also minimize the difference between that time and sunrise.