
Why the U.S. Wants To End the Link Between Time and Sun - joeyespo
http://online.wsj.com/article_email/SB112258962467199210-lMyQjAxMTEyMjIyNTUyODU5Wj.html?mod=wsj_valetleft_email
======
freehunter
I fail to see how this is an attack on science or on Europe. That's just
hyperbole. Making time consistent to prevent having to add time or remove time
just makes sense. Time is a unit of measurement. We don't redefine the foot
just because the new king has 10" feet instead of 12" feet. Time being
connected to the sun is a relic of the days before accurate time-keeping
methods. One day should always be one day.

To rebut my own argument, I suppose one could say that noon should always be
noon, regardless of how long the day is. The prevalence of daylight-saving
time in the US might disagree with that though.

~~~
lutusp
> I suppose one could say that noon should always be noon ...

Yes, but by allowing our clocks to go out of sync with the natural time of
noon, a relationship controlled by orbits rather than clocks, this proposal
would prevent that. Over time noon (highest solar position in the local sky)
would drift away from noon as given by a clock.

I especially like the part where this proposal's advocates dismiss those who
use a sextant to locate themselves on the ocean. I personally required this
clock consistency to navigate my boat during my around-the-world sail, after
my hi-tech satellite receiver expired.

This is not to argue that there's only one good argument here -- both
arguments are reasonable. Unfortunately, they differ in the most basic way.

If we stick to 86,400 seconds in a day and don't allow leap-seconds,
eventually daylight will happen at midnight -- either that or we will require
leap-hours or even leap-days (as happened in Europe during the transition from
the Julian to the Gregorian calendars).

If we continue to allow leap-seconds, all sorts of chronological record-
keeping will continue to be more complex than it needs to be.

As with all truly interesting problems, there's no easy answer.

~~~
freehunter
How long would it take for noon to be mid-night (as in middle of the night)?
Centuries? By then, one would hope we're dealing with the bigger issue of how
to coordinate time between two or more different planets or solar systems. As
it stands, a certain section of scientists have to do the translation between
the length differences of Earth days and Martian days.

It does provide a nice discussion point.

~~~
lutusp
> How long would it take for noon to be mid-night (as in middle of the night)?
> Centuries?

Much longer. But the practical difficulties would appear right away, when the
time "error" is still measured in seconds. As I said earlier, both sides of
this issue have perfectly valid points to make.

------
nextstep
I read through nearly the whole article before I realized this was from 2005.
What ever happened to this proposal?

~~~
Codhisattva
We just had a leap second June 30 so the proposal must have been scrapped.

edit to add link
[http://en.wikipedia.org/wiki/Leap_second#Proposal_to_abolish...](http://en.wikipedia.org/wiki/Leap_second#Proposal_to_abolish_leap_seconds)

~~~
lmm
As per your link, it's not that the proposal's been scrapped so much as the
decision's been postponed until 2015.

------
jackta101
This article is 7 years old and irrelevant. In fact a leap second was insert
in June this year.

~~~
wl
It may be seven years old, but it's not irrelevant. People are still
discussing this proposal. The article is the best explanation I've seen of
this issue to date.

Here's a more recent article posted here a few months ago:
[http://www.nytimes.com/2012/01/19/science/to-keep-or-kill-
lo...](http://www.nytimes.com/2012/01/19/science/to-keep-or-kill-lowly-leap-
second-focus-of-world-debate.html?_r=1)

Personally, I wish people would just leave UTC alone. If you don't want to
deal with leap seconds, use TAI, which was intended for such uses.

~~~
wmf
UTC and TAI are off by over 30 seconds; people can't accept a discontinuity
during the switchover. So what we really want is something like TAI-35. But
the real problem is coordinating everyone to switch timescales so we don't end
up with half the world on UTC and half on TAI-35. Also, I've heard there are
cases where people feel that they're legally obliged to use UTC because that's
the legal definition of civil time.

~~~
wl
TAI for the timekeepers and as an internal representation, UTC for display,
much like how many computers keep time in UTC and apply an offset to display
local time. Just because we have to deal with the legacy of POSIX doesn't mean
this isn't the right solution.

Yes, there are the obvious problems like the uncertainty of scheduling future
events in UTC because the insertion of leap seconds aren't known in advance.
But such things should be scheduled in TAI, anyway.

------
adjwilli
I was hoping this was a more radical proposal like
<http://en.wikipedia.org/wiki/Swatch_Internet_Time> was.

Our current way of measuring time is absurd. It starts as base 1000 with
milliseconds, then base 60 with seconds and minutes, then 24 for hours, 7 for
days, 4.3whatever for months or 28-31 however you want to track it.

I like that China only has one time zone for the entire country. We should all
go by UTC times regardless of our geographical position. But we should also
change our means of measuring time to work around whole base 10 numbers.

~~~
pixie_
Swatch Internet Time sounds awful.

Your idea to go from intuitive measurements of time to abstract measurements
sounds awful.

A single timezone for a 3,000 mile wide country sounds awful.

~~~
lmm
Single timezone for a large country works very well. It makes it much easier
to arrange a phone call or meeting with someone on the other side of it (you
still need to know what the difference is to know you're not asking them to be
there before breakfast or after supper, but you never get the failure mode
where you both think you've arranged a different time). And it can encourage
businesses to be flexible about working hours, since mandating 9-5 in all
their branches is obviously insane.

------
mdonahoe
I was expecting something more like Swatch Internet time.
<http://en.m.wikipedia.org/wiki/Swatch_Internet_Time>

Why must time be be earth centric? Imagine how hard it must have been for
Copernicus to convince everyone to use his model. Lazy programmers isn't as
compelling argument, but it has similarities.
<http://en.m.wikipedia.org/wiki/Copernican_Revolution>

Non-rhetorical questions: Does the Mars Curiousity rover use leap seconds?
Does it have Martian time too?

~~~
lutusp
> Does the Mars Curiousity rover use leap seconds? Does it have Martian time
> too?

Both the Mars Curiosity rover, and its operators, use the Mars day duration
(which is 24h 39m 35.24409s), but with time measured in "normal" seconds. The
JPL people directly responsible for this project even switch to a Mars clock
in their personal lives.

------
agwa
> leap seconds present a "risk to air travel in the future" because a glitch
> might shut down traffic-control systems.

This downright scary if true - a system that's not robust and fault tolerant
enough to withstand a leap second bug without putting lives in danger is going
to suffer from other bugs which will put lives in danger. Since software
development practices actually tend to be very paranoid when it comes to air
travel, I suspect this is really a scare tactic to garner support for
abolishing the leap second.

> the U.S. has proposed adding in a "leap hour" every 500 to 600 years, which
> also accounts for the fact that the Earth's rotation is expected to slow
> down even further. That would be no more disruptive than the annual switch
> to daylight-saving time

I'm incredulous. Daylight savings time effectively works by changing your
timezone offset from UTC. UTC itself doesn't change. Daylight savings time is
actually very disruptive to programs, and the solution is to just use UTC for
everything. A "leap hour" would presumably require changing the UTC-equivalent
itself. I guarantee you that no one will actually code for such a rare event,
which will make it a big and scary flag day which will get postponed
repeatedly while everyone prepares (probably by bringing a bunch of legacy
programmers out of retirement if software still exists by then). The only
thing appealing about this is that we'll all be long dead by then.

~~~
wmf
_A "leap hour" would presumably require changing the UTC-equivalent itself._

Earlier I proposed exactly the opposite. Never change UTC, just redefine your
timezone to create an apparent leap hour. Since we already do this twice a
year in many countries, it should be less of a problem.

~~~
agwa
Interesting idea! So basically every several hundred years we would shift the
center of time farther and farther away from Greenwich. That explains why the
British are opposed. I was thinking timezones would stay relative to Greenwich
and the "leap hour" would be thousands of accumulated leap seconds applied at
once. Your proposal sounds better.

------
jmvoodoo
I'm definitely looking forward to this debate when/if we ever have a permanent
mars colony. Will they still use earth/solar time? Use mars/solar time? Some
compromise between the two? I imagine someone living on mars could give two
shits if the earth/solar time was off by a few seconds, and I definitely don't
want to be responsible for handling two entire time systems in my code.

~~~
cwe
40 extra minutes in a martian day definitely make things interesting. Going
further, how will time work when we're stationed around Saturn's moons? We
will probably need some universal units of time that work regardless of how
long it takes you to rotate around the sun. (Stardates?)

~~~
lmm
Seconds since epoch is good enough for almost all purposes until you're moving
at ~10% of the speed of light; they'll be fine for computer timestamps as long
as acceleration and deceleration are gradual. So I don't think we'll need any
new universal units of time, only new local units of time, and I'm not even
sure about that. For mars, just extending the day until 24:40 = 00:00 seems
reasonable enough. For Saturn's moons the sun is faint enough that keeping
"earth time" is probably reasonable - whether it's solar day or solar night
will make very little difference to most people's lives, I would think.

------
001sky
_But adding these ad hoc "leap seconds" -- the last one was tacked on in 1998
-- can be a big hassle for computers operating with software programs that
never allowed for a 61-second minute, leading to glitches when the extra
second passes. "It's a huge deal," said John Yuzdepski, an executive at
Symmetricom Inc., of San Jose, Calif., which makes ultraprecise clocks for
telecommunications, space and military use..._

Isn't this the tail wagging the Dog? Crappy programming leads the UN to
redefine TIME for the whole plannet? There are few truly golobal, hitsorical
markers of culture shared by human societies. Accross continents, races and
millenia. Solar time is one of them.

How about: Don't fix what ain't broke. Fix that which is?

 __Sorry for the Rant __

__________

Edit:

As pointed out elsewhere in the comments. This proposal was from 2005, and is
apparently no longer on the table. Cooler heads appear to have prevailed.

~~~
ilcavero
you are wrong in your rationale because crappy programming cannot be fixed and
together with the current time definition it causes big problems to many, on
the other hand changing the time definition causes problems to whom? astronomy
purists?

~~~
001sky
What are your definitions of "cannot be fixed" "Many" and "Problems"?
Biological clocks and cellular metabolism are tied to daylight, amongst other
things. Talk about programming that cannot be fixed! Does that make 6 billion
astronomy purists ;) ?

Edited: For levity

------
acomjean
Its all about point of reference. When I worked with radar we liked GPS time,
always increasing so its easy to get a difference. But for locating the sun
and sun rise, earth time is useful (those griping astronomers have a point).

We figured it out, and it wasn't too bad. Some good time libraries would go a
long way...

------
blahedo
Fun trivia: the Keith Winstein that authored this article (in 2005) is the
same one that is now lead developer on mosh
(<http://news.ycombinator.com/item?id=3819382>)

------
sonnekki
Leap seconds are a work-around to make the 24-hour clock keep time correctly.
The reason so many problems occurred was a combination of insufficient
programming, but also the affect an inaccurate system.

I'm not sure what a correct system should be, but I know that it can't be
based on the Earth, the sun, or any one galaxy. In order to have accurate
time, it must be external to all of these things, like a meter stick is to an
object.

The possible problem with this is that there will come a time when "3:00 pm"
is in the middle of the night, the time to wake up for work will always
"change".

edit: more thoughts

~~~
patheman
"3:00 pm" is in the middle of the night, the time to wake up for work will
always "change"..

well, one time .. but do you !really! care about how the folks in +600 yrs
measure time? I'd guess they invent some kind of "glacial-period-light-saving-
time" by then...

~~~
kamjam
I know it's a joke, but it's lazy programming/lazy thoughts like this that
caused the issues with the systems in the first place :)

Although I still don't fully understand why leap seconds caused such a problem
- we can handle leap years and we can handle daylight savings, surely this is
just another clock correction action such as these?

~~~
freehunter
The problem with programming for a leap second is you don't know when a leap
second will occur. Compare this to a leap year, which happen every 4 years,
always. Leap seconds are sporadic [1]. Programming a clock to accept the time
of 11:59:60 only on occasion is trivial in a web app, but slightly more
complex in a firmware or high-reliability system like flight controls.

[1]
[https://en.wikipedia.org/wiki/Leap_second#Insertion_of_leap_...](https://en.wikipedia.org/wiki/Leap_second#Insertion_of_leap_seconds)
(see the chart at the side)

~~~
kamjam
Thanks for the explanation, makes sense. I see what you mean about the
sporadic nature of the insertions!

------
pixelcort
> Ending leap seconds would make the sun start rising later and later by the
> clock -- a few seconds later each decade. To compensate, the U.S. has
> proposed adding in a "leap hour" every 500 to 600 years...

So it's not abandoning the shifting so much as putting it off into a larger
interval, the leap-hour.

Today, that interval is the second. Today, we don't adjust for partial
seconds; this proposal just moves the adjustment interval way out.

Perhaps somewhere in the middle like leap-minutes would be better. This would
thus occur every 60-90 years.

------
weavejester
Alternatively, just store times using system that's already divorced from the
rotation of the Earth, such as Unix Time.

~~~
wmf
Isn't Unix time UTC, which includes leap seconds which is what is causing all
these glitches?

~~~
weavejester
No, Unix Time is the number of seconds since a fixed origin. In human time the
origin is usually expressed in terms of UTC time, but Unix Time itself is
divorced from Earth's rotation. Leap seconds only have to be taken into
account when converting into human dates and times.

------
sageikosa
But whose clock do we trust? No clock on this planet is in an inertial frame
of reference. Over time, clocks at different latitudes and altitudes will
diverge because they are moving at different speeds, even if they have the
same atomic decay "tick" process. Which do we pick as the standard?

Even if one clock were picked, observations of when the clock ticked would
vary over the planet as well.

Astronomical distant fixed points are more stable over long time spans than
Earthbound clocks or the Earth's rotational and orbital characteristics, and
the relative displacement with regard to Earthbound distance is negligible.

------
alttab
This all sounds about right to me - the US government's increasing arrogance
on behalf of US businesses, that is.

------
cyarvin
("America! Fsck yeah!" I mean, some of us USans, proud sponsors of WIPO and
other fine agreements, never thought we'd see the day our international
representatives would be in the right. Sadly that day appears to be... 2005.)

Leap seconds are an abomination against nature: they make _math not work on
time_. In chronological (atomic) time, math on time is stateless and
referentially transparent. Like math. In sidereal time, it... isn't.

The general use of sidereal time is a gigantic global complexification with
trivial cosmetic benefits to one specialized profession - astronomy.
Unfortunately, it is also the astronomers who have been put in charge of time
standardization, so the disaster will probably continue.

The right way to treat time as a programmer, if you're really serious about
time, is to treat sidereal time as a display mode, like a timezone, and work
internally in proper chronological time (eg, GPS time). Unfortunately the leap
second system is a timezone that varies over time. But at least the complexity
is isolated in the presentation layer.

