
Daylight Saving Time is a huge mess - ColinWright
http://www.johndcook.com/blog/2011/11/06/dst-is-a-mess/
======
bdhe
Interesting trivia: Daylight savings might only be worth the effort for
countries in the middle-latitude range (largely Europe, Americas and
Australia/NZ). The closer you are to the equator, there's little variation in
daylight and thus it doesn't matter.

Surprisingly the farther up north you are, there is _so much_ variation that 1
hr doesn't really matter when your days go from 19 hrs long to less than 5
hrs. So Iceland for eg. does not practice Daylight Saving time.

There should be a better reference: <http://wwp.greenwichmeantime.com/time-
zone/europe/iceland/>

~~~
JoeAltmaier
Doesn't "middle-latitude" cover most of the world's population?

~~~
bdhe
That's true, but note that China and India, together with 2.6 billion / 7
billion people don't have daylight saving. The former for political, the
latter for latitude reasons. Another big country to abolish it recently is
Russia.

~~~
Pyrodogg
Just to note that Russia abolished the switching of clocks but didn't really
go back to 'standard time'.

> Russia moved its clocks one hour forward to daylight saving time on March
> 27, 2011. According to the new legislation this is now the country's new
> standard time. As a result, all of Russia's nine time zones will be
> permanently two hours ahead of mean solar time, which corresponds to the
> position of the sun at a given longitude.
> <http://www.timeanddate.com/news/time/russia-dst-law.html>

------
TamDenholm
This guy makes absolutely amazing videos on a number of subjects explaining
things in really simple terms. He made one explaining Daylight Savings Time
here: <http://www.youtube.com/watch?v=84aWtseb2-4>

His blog with other videos is here: <http://blog.cgpgrey.com/>

------
mildweed
As a programmer, I hate DST. In fact, I also hate time zones, leap years and
horseradish sauce. All are unnecessarily complicated. Now, I don't think the
OP's proposal of having everyone go GMT/UTC would work, a simpler solution to
measuring this thing we call time has got to exist.

The only thing keeping me from trying to solve this problem with a new
standard is this: <http://xkcd.com/927/>

~~~
ars
Leap years are unnecessarily complicated? No, I think they are exactly as
complicated as they should be. And horseradish sauce is both tasty, and quite
easy to make.

And not having timezones would be even more complicated.

------
cromulent
Yeah, it's complicated having different times in different places in different
seasons. A mess? Perhaps. Useful and rational anyway? Perhaps.

"Time is an illusion. Lunchtime doubly so." - Douglas Adams.

------
rmc
This article promotes a few simplistic ways to think about time. First it says
that the "UTC is the time in England minus the day light savings time", which
is technically correct, however it's a bad metaphore to give, especially to
people in UK. There are many who think "GMT includes daylight sayings time",
and so "UTC = Time in England" can make people think that UTC includes
daylight savings.

It's also very simplistic to say that a city is on UTC plus/minus X hours,
_because_ daylight savings time messes that up. It's much easier to use tzdata
format such as "America/Houston", and use a library that uses the tzdata
database. Then you never have to worry about when Houston changes from UTC-6
to UTC-5. No point in making work for yourself!

(Also lingustic observance: Seems to be the Americans who say "Daylights
savings time" and UK English sayings "Summer Time", anyone else notice this?)

~~~
seabee
It's Europe-wide in fact. British Summer Time (+1) and Central European Summer
Time (+2). Would be interested in the history behind the difference in
terminology though.

~~~
blahedo
I'm guessing it has something to do with a lot of people confusing which
direction is the "savings" time. As in, did we just enter or leave DST? (I
hear people making this mistake or its converse every year.) "Summer" time is
harder to make that mistake with.

------
IgorPartola
Daylight savings and time zones are annoying and DST especially could use some
clean up. However, it seems to be a necessary evil. The problem with "Let's
just adopt UTC universally" is that now we are pushing the problem of
determining whether the person you want to schedule a meeting with is awake
when you are from few centralized authorities to each and every individual.
Right now, if I tell you that it's 2pm where I am, you can assume that I am
awake. If I tell you that it's 6pm UTC, that means nothing until you make the
conversion. This conversion gets harder the more UTC is used as the standard.
If we still have time zones, then it means you need to look up what timezone I
am in, then make the conversion and determine what the local time for me is.
If we don't even have time zones, we are stuck with having to look up
approximate areas and essentially estimating time zones.

The linked article seems to suggest that I should have written that as 2pm
-0400 UTC, which is sort of the best of both worlds. This way your you can
make the conversion to your own time much easier. There may be something to
this, but I am not sure it is enough to get everyone to agree on proper DST
and to get rid of timezones like the ones used in Arizona.

~~~
mikeash
Right now, if you need to schedule meetings during a certain period with
geographically separated people, you need to know each person's hours of
availability and their time zone so you know how to convert them all to
match.. If UTC were adopted universally, you'd need to know each person's
hours of availability. You reduce, not increase, the amount of information
that needs to be passed around.

~~~
jleader
For most people, though, hours of availability can be more or less implicit.
If I'm scheduling a phone call with a business person who works in an office,
I can assume that their availability will probably be highest sometime around
10AM to 5PM in their local time zone. This is less true for hackers, and for
self-employed people who don't spend a lot of time interacting with office
workers, of course.

~~~
luriel
> For most people, though, hours of availability can be more or less implicit.

For most people I'm quite sure hours of availability can _not_ be guessed
based on what timezone they are in, most people are busy, their windows of
availability are much more narrow than 8am-5pm, and surprisingly often they
are available outside that range.

------
Aloisius
Personally, I wish the sun came up at exactly 7 am local time every morning
plus or minus say, 30 minutes so you could make largish time zones and
anything that had to be coordinated cross-time zone was scheduled in UTC.

Yes, this would mean that clocks would adjust by minutes per day, but at least
I'd wake up with dawn every morning.

Think how much money we could save in alarm clocks!

~~~
repsilat
There's a strange upside to this solution - because it's obviously so
difficult to "get right" people will probably let other people solve it for
them (correctly) instead of writing yet another ad-hoc "mostly correct"
implementation.

------
tobylane
Last week (when the UK change was) there was the bi-perennial news about if we
need it or not, and basically the Scottish don't want it the way we want it,
and just because they might soon be independent doesn't change that.
<http://www.bbc.co.uk/news/magazine-12536056>

------
russell
I like daylight, so I'm a DST fan. In 1973 we had year round DST, But it was
abolished the next year. Why you ask? Hey this is the US, to save the children
of course. A couple of kids were killed waiting in the dark for their school
bus, with a resulting national uproar and a switch back to ST/DST.

The internet company where I work has an interesting solution to the problem.
At the fall change they shut down all the servers at 12:50 and restart them at
1:10. Total downtime is 80 minutes. I have always thought that UTC would have
been simpler.

Another company made monitoring systems for electrical power distribution,
which could not be shut down for the convenience of IT, o it had to deal with
a 23 hour day in the spring and a 25 hour day in the fall.

~~~
gst
That's not a solution, but sounds more like a thedailywtf.com posting. DST has
not been any problem on most operating systems for a long time now. And for
well written applications it should not be any issue either.

~~~
arohner
Having supported python & rails webapps running on postgres, the biggest
problem is not the OS, but the DB and programming language.

Postgres for example, can't change timezones without rebooting. Python &
Ruby/Rails both have poor support for handling timezones properly. The proper
solution is to of course run the backend in UTC all the time, and just convert
to local time when displaying, but if you already have legacy code...

------
zanny
It would only take us one generation to just switch over to everyone using UTC
in a 24 hour clock and we could get rid of time zones, DST, AM / PM, and all
the other time crap built up over the last thousand years around people
wanting to always get up at 7 am.

But then again, if the US can't implement the metric system, I have no idea
how ~6.5 billion people (those not in GMT right now) would learn that dawn
does not always mean 7 am and dusk does not mean 7 pm.

But think of the benefits! Schedule an appointment in CA from NY, and you
don't have to explode your brain thinking about time conversions. New show at
20:00! Wait, 8, is that am or pm? No problem!

Just like the metric system! D:

------
charlesju
I use <http://www.wolframalpha.com/> to do time comparisons.

For instance, if I type in "10pm Taipei" it will tell me the corresponding
time here (SF, CA), which is 6am PST.

~~~
mrud
I use <http://www.worldtimebuddy.com/> (discovered it on hn).

It has a really simple and nice interface and visualizes the different time
zones very well.

~~~
BerislavLopac
Thankyouthankyouthankyou I have stupidly lost the link to this site and was
unable to find it since. I've also used
<http://timeanddate.com/worldclock/meetingtime.html>, but it's not nearly that
usable.

------
sixbrx
Yeah, sleep disruption in the spring is a bad thing. Sleep disruption in
general has been known to cause increased risk of accidents, I don't know if
this has been specifically tied to DST or not. If so it wouldn't be
exaggerating to say that DST kills people.

Also it's a mess for IT, with software having to be upgraded for timezone
database updates. We had an awefull time at my workplace caused by a java
timezone update, that had to occur out-of-band vs. the usualy upgrade cycle.
DST disposition can vary by _county_ in the US for fucks sake... It's a big
mess.

------
slyall
I find daylight saving useful. It means that instead of an extra hour of
daylight from 5am-6am I get an extra hour of daylight between 8pm and 9pm.

Last summer I went to Queensland which doesn't having daylight saving. I woke
up at 6am with bright sunlight coming though my window while it was dark by
7pm.

That is the point of daylight saving, move the extra hours of daylight to the
evening when they are useful not "wasting" them first thing in the morning
when most people can't take advantage of them.

~~~
tsotha
Was there something in Queensland that prevented you from waking up earlier?
If you wanted more time in the morning, why didn't you wake up at 5 o'clock?

I'm okay with people shifting their hours around, but why should I be forced
to do the same?

~~~
slyall
I didn't want more time in the morning I wanted it in the evening. I was at
something from 9-5 and then out in the evening with people.

The way society works is that things happen in the evenings, the number of
things to do a 5-7am to take advantage of extra sunlight is a lot more
limited.

------
mvkel
Because when I'm trying to close a deal with a customer, and I ask when
they're free, I'll really impress them by saying, "oh, you're in UTC-5; we're
in UTC-6"

How does the article referenced make anyone's life easier? It forces everyone
into doing an equation instead of just one person (the host of the meeting)

------
kmm
It's a prime example of humanity being stuck in its old ways. During both
World Wars, the Germans put Belgium to their timezone, UTC+1. Almost 70 years
later, this still hasn't been changed. With as result that in the summer,
we're two hours ahead of the correct time.

~~~
rmc
The Germans did the same with France (which is due south of England, and hence
straddles the 0͏° of longitude), and yet it's on CET (central european time).

------
stretchwithme
Lets just have a referendum on abolishing DST. We can certainly do that in
California. Arizona does't have it, so we should be able to dump it. Maybe
that will be the beginning of the end.

------
vegai
Some light at the end of the tunnel: Russia decided to scrap the whole system
this year! I hope they will stick with that absolutely brilliant decision.

~~~
radley
Actually, they stuck with Daylight Saving Time and scrapped regular clock
time...

~~~
mikeash
That's just a technicality over which time zone they decided to stick with.
DST all year round is fundamentally equivalent to standard time all year round
when it comes to this.

------
jamesbritt
Related discussion: <http://news.ycombinator.com/item?id=3197827>

------
noveltyaccount
Thanks OP for getting it right. It's Daylight Saving Time. Not savings. As
with labor-saving device, daylight-saving time.

------
Duckpaddle2
Don't like it, blame a golfer.... The golf course owners were a huge lobby for
DST!

------
kiba
Yes, this is the system that I like. I don't give a damn whether or not I live
near the equator, in-between, north pole, etc. (for the record, I live in a
place where the DST could be considered "useful")

Don't mess with my time.

Alas, hell is other people.

