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  • Every year some countries move their clocks forward in the spring only to move them back

  • in the autumn. To the vast majority of the world who doesn’t

  • participate in this odd clock fiddlingit seems a baffling thing to do. So what’s

  • the reason behind it? The original idea, proposed by George Hudson,

  • was to give people more sunlight in the summer. Of course, it’s important to note that changing

  • a clock doesn’t actually make more sunlightthat’s not how physics works.

  • But, by moving the clocks forward an hour, compared to all other human activity, the

  • sun will seem to both rise and set later. The time when the clocks are moved forward

  • is called Daylight Saving Time and the rest of the year is called Standard Time.

  • This switch effectively gives people more time to enjoy the sunshine and nice summer

  • weather after work. Hudson, in particular, wanted more sunlight so he could spend more

  • time adding to his insect collection. When winter is coming the clocks move back,

  • presumably because people won’t want to go outside anymore.

  • But, winter doesn’t have this affect on everyone.

  • If you live in a tropical place like Hawaii, you don’t really have to worry about seasons

  • because they pretty much don’t happen. Every day, all year is sunny and beautiful

  • so christmas is just as good of a day to hit the beach as any other. As so, Hawaii is one

  • of two states in the Union that ignore daylight saving time.

  • But, the further you travel from the equator in either direction the more the seasons assert

  • themselves and you get colder and darker winters, making summer time much more valuable to the

  • locals. So it’s no surprise that the further a country is from the equator the more likely

  • it uses daylight saving time. Hudson proposed his idea in Wellington in

  • 1895 – but it wasn’t well received and it took until 1916 for Germany to be the first

  • country to put it into practice. Though, the uber-industrious Germans were

  • less concerned with catching butterflies on a fine summer evening than they were with

  • saving coal to feed the war machine. The Germans thought daylight saving time would

  • conserve energy. The reasoning goes that it encourages people to stay out later in the

  • summer and thus use less artificial lighting. This sounds logical, and it may have worked

  • back in the more regimented society of a hundred years ago, but does it still work in the modern

  • world? That turns out to be a surprisingly difficult

  • question to answer. For example, take mankind’s greatest invention:

  • AIR CONDITIONING. The magic box of cool that makes otherwise uninhabitable sections of

  • the world quite tolerable places to live. But, pumping heat out of your house isn’t

  • cheap and turning on one air conditioner is the same as running dozens of tungsten light

  • bulbs. If people get more sunshine, but don’t use

  • it to go outside then Daylight Saving Time might actually cost electricity, not save

  • it. This is particularly true in a place like

  • Phoenix: where the average summer high is 107 degrees and the record is 122.

  • If you suggest to an Arizonian to change their clocks in the summer to get more sunshine,

  • they laugh in your face. More sun and higher electricity bills are not what they want which

  • is why Arizona is the second state that never changes their clocks.

  • Another problem when trying to study daylight saving time is rapid changes in technology

  • and electrical use. And as technology gets better and better and

  • better more electricity is dedicated to things that aren’t light bulbs.

  • And the lure of a hot, sweaty, mosquito-filled day outside is less appealing than technological

  • entertainments and climate-controlled comfort inside.

  • Also the horrifically energy in-efficient tungsten light bulbs that have remained unchanged

  • for a century are giving way to CFLs and LEDsgreatly reducing the amount of energy

  • required to light a room. So, even assuming that DST is effective,

  • it’s probably less effective with every passing year.

  • The bottom line is while some studies say DST costs more electricity and others say

  • it saves electricity, the one thing they agree on is the effect size: not 20% or 10% but

  • 1% or less, which, in the United States, works out to be about $4 per household.

  • $4 saved or spent on electricity over an entire year is not really a huge deal either way.

  • So the question now becomes is the hassle of switching the clocks twice a year worth it?

  • The most obvious trouble comes from sleep depravation

  • an already common problem in the western world that DST makes measurably

  • worse. With time-tracking software we can actually

  • see that people are less productive the week after the clock changes. This comes with huge

  • associated costs. To make things worse, most countries take

  • away that hour of sleep on a Monday morning. Sleep depravation can lead to heart attacks

  • and suicides and the Daylight Saving Time Monday has a higher than normal spike in both.

  • Other troubles come from scheduling meetings across time zones.

  • Let’s say that your trying to plan a three-way conference between New York, London and Sydney

  • not an easy thing to do under the best of circumstances but made extra difficult

  • when they don’t agree on when daylight saving time should start and end.

  • In the spring, Sydney is 11 hours ahead of London and New York is five hours behind.

  • But then New York is the first to enter Daylight Saving Time and moves its clock forward an

  • hour. Two weeks later London does the same. In one more week, Sydney, being on the opposite

  • side of the world, leaves daylight saving time and moves its clock back an hour.

  • So in the space of three weeks New York is five hours behind London, then four hours

  • and then five hours again. And Sydney is either 11, 10 or 9 hours from London and 16,

  • 15 or 14 hours from New York. And this whole crazy thing happens again in

  • reverse six months later. Back in the dark ages, this might not have

  • mattered so much but in the modern, interconnected world planning international meetings happens

  • 1,000s and 1,000s of times dailyshifting and inconsistent time zones isn’t doing

  • netizens any favors. And, countries aren’t

  • even consistent about daylight saving time within their own borders.

  • Brazil has daylight saving time, but only if you live in the south. Canada has it too,

  • but not Saskatchewan. Most of Oz does DST, but not Western Australia, The Northern Territory

  • or Queensland. And, of course, the United States does have

  • DST, unless you live in Puerto Rico, the Virgin Islands, American Samoa, Guam, the Northern

  • Marianas Islands or, as mentioned before Hawaii and Arizona.

  • But Arizona isn’t even consistent within itself.

  • While Arizona ignores DST, the Navaho Nation inside of Arizona follows it.

  • Inside of the Navaho Nation is the Hopi Reservation which, like Arizona, ignores daylight saving

  • time. Going deeper, inside of the Hopi Reservation

  • is another part of the Navaho Nation which does follow daylight saving time.

  • And finally there is also part of the Hopi Reservation elsewhere in the Navaho Nation

  • which doesn’t. So driving across this hundred-mile stretch

  • would technically necessitate seven clock changes which is insane.

  • While this is an unusual local oddity here is a map showing the different daylight saving

  • and time zone rules in all their complicated gloryit’s a huge mess and constantly

  • needs updating as countries change their laws. Which is why it shouldn’t be surprising

  • that even our digital gadgets can’t keep the time straight occasionally.

  • So to review: daylight saving time gives more sunlight in the summer after work, which,

  • depending on where you live might be an advantageor not.

  • And it may (or may not) save electricity but one thing is for sure, it’s guaranteed to

  • make something that should be simple, keeping track of time, quite complicated

  • which is why when it comes time to change the clocks is always a debate about whether or not we should.

Every year some countries move their clocks forward in the spring only to move them back

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Daylight Saving Time Explained

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    Why Why   posted on 2013/04/14
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