Beta

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

US DoD Poll On Leap Seconds

kdawson posted more than 5 years ago | from the great-leap-forward dept.

Earth 314

@10u8 writes "For time scales to leap, or not to leap, has been the question here before. The ITU-R will be considering leap seconds again in a few weeks. This week the USNO posted a survey about leap seconds by the US DoD. The issue has civil implications as well as technical ones, and there is a demonstrated way to respect the history, remove leaps from navigation and POSIX time, yet keep the sun overhead at noon."

cancel ×

314 comments

Sorry! There are no comments related to the filter you selected.

Why did you Brits send us... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#24926687)

one of your homeless citizens to host the VMAs? At least give him a shave and a shower befire sending him our way.

Re:Why did you Brits send us... (-1, Offtopic)

sexconker (1179573) | more than 5 years ago | (#24926715)

I don't know who hosted the VMAs or whatnot or if you're even referencing something that actually happened.

But I can only assume you're talking about Michael Moore.

Re:Why did you Brits send us... (0, Offtopic)

neokushan (932374) | more than 5 years ago | (#24926985)

Quick! Someone say "Russell Brand called George Bush a retard" for some cheap +1 informative mods.

Then spend the rest of your day wondering if you were modded informative for explaining the situation, or for repeating what Russell said.

Then realise that if anyone knew what you were thinking, they'd probably mod you +1 Troll.

Then realise you spend too much time on slashdot.

Then realise you've got no girlfriend.

Then realise you'll probably never have a girlfriend.

Then realise you've got no life.

Then mod yourself +1 offtopic.

Re:Why did you Brits send us... (-1, Offtopic)

BitterOldGUy (1330491) | more than 5 years ago | (#24927189)

Then realise that if anyone knew what you were thinking, they'd probably mod you +1 Troll.

Mod points make you psychic?

Re:Why did you Brits send us... (-1, Offtopic)

neokushan (932374) | more than 5 years ago | (#24927267)

No, they make you feel like a big man.

So many articles to read. (-1, Offtopic)

BitterOldGUy (1330491) | more than 5 years ago | (#24926689)

How the hell is anyone to get frist psto?!?

Oh wait....

The force is strong with this one... (-1, Offtopic)

Tetsujin (103070) | more than 5 years ago | (#24926933)

Wasn't Frist Psto one of the Jedi who fought in the clone wars??

Re:The force is strong with this one... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#24926995)

No, that was Frost Psti, but I understand your confusion: It's a common mistake.

Re:The force is strong with this one... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#24927159)

I thought that was a Batman villain.

Are leap seconds really all that important? (4, Insightful)

NoobixCube (1133473) | more than 5 years ago | (#24926697)

I thought we had leap years to take care of the discrepancy between our calendar and the actual orbit around the sun. Would a leap second even be made longer by any noticeable amount? What about sporting events? Someone who misses out on a world record by a tiny bit would complain that the record h older had more leap seconds in his race! (Okay, that one was a joke, but the rest I'm serious about)

Re:Are leap seconds really all that important? (5, Funny)

Anonymous Coward | more than 5 years ago | (#24926723)

Compare absolute time vs relative time vs elapsed time vs hammer time...

Re:Are leap seconds really all that important? (5, Funny)

xstonedogx (814876) | more than 5 years ago | (#24927011)

I dunno. When it's Miller Time all those other times kinda look alike.

Re:Are leap seconds really all that important? (0)

Anonymous Coward | more than 5 years ago | (#24927399)

And the ugly chick at the bar starts to look good

Re:Are leap seconds really all that important? (3, Insightful)

maxume (22995) | more than 5 years ago | (#24926765)

The leap seconds do the same thing as the leap years (each leap day moves the calendar closer to the orbit, but not exactly to the orbit).

Leap seconds fix a diferent problem (5, Informative)

EmbeddedJanitor (597831) | more than 5 years ago | (#24926771)

Leap days correct our orbit around the sun to keep December/January in the middle of winter for the Northern Hemisphere.

Leap seconds correct for the rotation of the earth to keep the sun above at noon.

If we dispense with leap seconds then this relationship will slowly change and noon will eventually be dark.

Re:Leap seconds fix a diferent problem (2)

NoobixCube (1133473) | more than 5 years ago | (#24926859)

I suppose I'd know that if I'd R'd TFA... :P

Or played with GPS etc (2, Insightful)

EmbeddedJanitor (597831) | more than 5 years ago | (#24926975)

Keeping leap seconds synced is pretty important across comms networks.

Re:Or played with GPS etc (0)

Anonymous Coward | more than 5 years ago | (#24927183)

Re:Or played with GPS etc (3, Interesting)

snowraver1 (1052510) | more than 5 years ago | (#24927489)

Not surprised, there is really no need to. Your GPSr doesn't care what time it is in human terms, it just needs a number that it can use to caclulate signals relative to each other. That could be anything, possibly even the number of seconds that have passed since 1970.

I would be more surprised if they acutally didupdate GPS satellites with leap second fixes. I would think you would have to recilibrate all the satellites.

*Note* I do office magic, not satellite magic.

Re:Or played with GPS etc (4, Informative)

digitig (1056110) | more than 5 years ago | (#24927517)

That's correct, because correcting the epoch for leap seconds would cause glitches in positioning as the corrections were applied. Instead, GPS broadcasts a UTC correction so the receiver can convert to UTC if required: ahref=http://www.navcen.uscg.gov/pubs/gps/sigspec/gpssps1.pdfrel=url2html-16574 [slashdot.org] http://www.navcen.uscg.gov/pubs/gps/sigspec/gpssps1.pdf>

Re:Leap seconds fix a diferent problem (0)

Anonymous Coward | more than 5 years ago | (#24927007)

How about we have a leap hour? It would only need to occur every 1/3600 times that we do a leap second and the reasoning for it would make a whole lot more sense to the general public.

It bothers me the amount of money that is being spent researching this problem.

Re:Leap seconds fix a diferent problem (2, Interesting)

nsayer (86181) | more than 5 years ago | (#24927245)

The trouble with that is twofold:

1. Ordinary people who don't take note of such things can have their clocks be off by a second (or even a few) and still get along in their ordinary lives. That would not be the case if the government announced that there was going to be a leap hour inserted this year and they missed it.

2. Any semi-periodic event that must be noted and accommodated by the general public that cannot be calendared years in advance is virtually guaranteed to be a snarling mess.

Re:Leap seconds fix a diferent problem (1)

wtfispcloadletter (1303253) | more than 5 years ago | (#24927447)

2. Any semi-periodic event that must be noted and accommodated by the general public that cannot be calendared years in advance is virtually guaranteed to be a snarling mess

We seem to get along just fine with the idiotic Daylight Savings Time and changing clocks twice a year. True those who are paying attention actually know which days those are. But the same could be done with a leap hour as those could be scheduled and known years in advance. Not that I agree with the concept of a leap hour, I think the very idea is moronic as I agree more with your first statement. People don't care or notice if their clocks are off by a few seconds or even a few minutes. If they happen to notice, they they make the minor adjustment and go on with their lives.

Re:Leap seconds fix a diferent problem (2, Interesting)

catmistake (814204) | more than 5 years ago | (#24927073)

Leap days correct our orbit around the sun to keep December/January in the middle of winter for the Northern Hemisphere.

While true, that is the intent, has any one noticed that this has failed over the last 20 years or so? When I was a child, Winter was Winter, and the first snow fall in the Northeast was usually by Thanksgiving. Over the past couple decades, the first snowfall seems to be pushing itself into late January, mid-February. Used to be, the harshest part of Winter was Dec-Jan, now it seems firmly seated in February. And why is it every year we see an Indian Summer smack in the middle of Winter? By my reckoning, we're now at least a month off (April frost brings May snot).

Re:Leap seconds fix a diferent problem (0)

Anonymous Coward | more than 5 years ago | (#24927125)

It syncs to astronomic time, i.e. how the earth rotates around the sun. You can see that by how long the days are and how high the sun is in the sky at noon.

The weather is a very different and very complex question that could not be predicted ahead of time like that. So by your reckoning, climate lags astronomic movement by a month now compared to 20 years ago? Depending on where you live, that's quite possible. But it's not something leap anythings could fix :)

Re:Leap seconds fix a diferent problem (1)

moderatorrater (1095745) | more than 5 years ago | (#24927155)

has any one noticed that this has failed over the last 20 years or so?

No. Labor Day was as cold in the valley as it usually is in the mountains this year, and trick or treating has consistently required coats for my family for the past 20 years.

Re:Leap seconds fix a diferent problem (1)

Hadlock (143607) | more than 5 years ago | (#24927193)

source? Pretty sure the latest recorded freeze in the DFW area has been april 14th for something like that for more than 30 years. when 80% of the US has only had scientifically accurate weather data for the last 100 year or so. pull up weather records for your area and post them, i'd be interested to see factual evidence support your theory.

Two Words (-1, Flamebait)

Xaositecte (897197) | more than 5 years ago | (#24927403)

Global Warming.

Re:Leap seconds fix a diferent problem (0)

Anonymous Coward | more than 5 years ago | (#24927427)

"Global warming... 'nuff said."

--Al "A.C." Gore

Yep... (4, Insightful)

msauve (701917) | more than 5 years ago | (#24927133)

and if anyone doesn't like leap seconds, all they have to do is use one of the time scales which don't use them, like TAI [wikipedia.org] .

It's exceedingly silly and stupid for people to keep trying to change UTC [wikipedia.org] so it doesn't track solar time. That what it was intended to do. If you made the wrong choice, live with it, or change time scales. If it's being forced on you, quityerbitchin', and convince whoever decided on UTC to change. Stop trying to turn UTC into something it isn't, there are other people out there who made an intelligent decision, and depend on it's characteristics.

Re:Leap seconds fix a diferent problem (1)

blantonl (784786) | more than 5 years ago | (#24927151)

My God your signature:

Engineering is the art of compromise.

And then this quote:

If we dispense with leap seconds then this relationship will slowly change and noon will eventually be dark.

Does slowly equal 20 years, or 20,000 years before we're dark? I mean really?!?

Re:Leap seconds fix a diferent problem (2, Funny)

nategoose (1004564) | more than 5 years ago | (#24927261)

You had me scared there for a little bit. I thought you were going to explain how dispensing with leap times was going to degrade our orbit and make us either fall into the Sun or fling out into deep space.

Re:Leap seconds fix a diferent problem (0)

Anonymous Coward | more than 5 years ago | (#24927433)

I think the whole issue is made more complicated than it is. The timescales where leap seconds are a hindrance obviously don't care at all about synchronicity to "natural" time as dictated by the rotations of the Earth. They are used in applications which care more about exact durations rather than points in time. That quite obviously means that these timescales should simply count (micro-, nano-, femto-)seconds from a defined point in time and leave the days and years to the timescales where these words make sense. "Human" time on the other hand, with it's days and years, should equally obviously be kept in sync with our movement through the solar system.

Re:Are leap seconds really all that important? (0)

Anonymous Coward | more than 5 years ago | (#24926847)

You're thinking of leap years, those are used to handle the year being having a fractional day. The leap seconds are inserted because the earth's rotation has a small but measurable instability. Some days really are longer than others (by a few milliseconds, anyway).

Not quite (4, Informative)

Deadstick (535032) | more than 5 years ago | (#24926709)

there is a demonstrated way to...keep the sun overhead at noon.

No there isn't, but you can make it culminate at noon.

rj

Re:Not quite (2, Funny)

moderatorrater (1095745) | more than 5 years ago | (#24926729)

Yeah, but anyone close enough to give the sun a nooner would get burned up.

Re:Not quite (1)

JustOK (667959) | more than 5 years ago | (#24926769)

so do it when its cloudy, d'uh!

Re:Not quite (1)

sconeu (64226) | more than 5 years ago | (#24926803)

<PARIS-HILTON>
That's Hot!
</PARIS-HILTON>

Re:Not quite (1)

Fear the Clam (230933) | more than 5 years ago | (#24927475)

No there isn't, but you can make it culminate at noon.

It depends where you are in your time zone. It's rare for the sun to be directly overhead at noon.

Kill DST instead!!!! (5, Insightful)

wealthychef (584778) | more than 5 years ago | (#24926731)

I'd be more interested in killing Daylight Savings Time than dealing with Leap Year.

Re:Kill DST instead!!!! (2, Insightful)

illegalcortex (1007791) | more than 5 years ago | (#24926781)

DST can be "fixed" by recording time in UCT. No such "fix" exists for leap seconds. With leap seconds, you're getting down to the fundamentals of how time is recorded, not how it is translated to local time.

Re:Kill DST instead!!!! (1)

corsec67 (627446) | more than 5 years ago | (#24926883)

Why don't you try to get everyone you interact with to use UTC, then?

The gp obviously wasn't talking about recording timestamps, which should be in UTC.

Re:Kill DST instead!!!! (1)

RanCossack (1138431) | more than 5 years ago | (#24926953)

The solution is obviously to use Unix timestamps for everything.

Re:Kill DST instead!!!! (1)

philspear (1142299) | more than 5 years ago | (#24926793)

Because it doesn't give you enough time during the day to sufficiently explain yourself on /.?

Re:Kill DST instead!!!! (0, Troll)

narcberry (1328009) | more than 5 years ago | (#24926811)

DST increases the productivity of the workforce. Just compare Arizona with the rest of the nation.

Re:Kill DST instead!!!! (0, Interesting)

Anonymous Coward | more than 5 years ago | (#24926833)

Why would you want to get rid daylight savings time? I would make the argument that we should extend it even more. I can't stand leaving for work when it's still dark, and getting off when the sun is starting to go down. My skin is already turning incandescent green from spending too much time in the office.

Think of how many lives daylight savings saves regarding traffic

Re:Kill DST instead!!!! (4, Funny)

CorporateSuit (1319461) | more than 5 years ago | (#24926879)

I'd rather have the sun on my face when I'm trying to wake up in the morning than hovering in my rearview while I'm trying to drive home.

Re:Kill DST instead!!!! (2, Interesting)

kpainter (901021) | more than 5 years ago | (#24926927)

Why would you want to get rid daylight savings time?

Because it is like cutting a foot off of one end of a blanket and sewing it on the other end and expecting to get a blanket that is a foot longer. Kind of dumb. If you want to get up when it is light, get up earlier. When should we all have to move the clock back and forth? Split the difference between DST and normal time and leave it. Who cares if the sun isn't overhead at exactly noon.

Re:Kill DST instead!!!! (1)

BagOBones (574735) | more than 5 years ago | (#24927097)

Not only that the blanket keep shrinking in the wash anyway, so moving the end around doesn't matter as the blanket will be too short in any direction in a few weeks anyway.

http://www.gaisma.com/en/dir/001-continent.html [gaisma.com]

Re:Kill DST instead!!!! (1)

Kent Recal (714863) | more than 5 years ago | (#24927211)

My thoughts *exactly*. That whole DST idea was broken from the very beginning and I wonder what could actually break if we just got rid of it right now?
I guess there would be some confusion in the first few years because millions of clocks and watches would still auto-adjust (and have to be fixed or replaced anyhow) but that's not so different to what we have today, twice every year.

Is there anything serious relying on DST that would break if DST suddenly went away?

Either way I think it's a safe bet that the savings in energy and money due to DST sum up to a negative value.
So why can't the people in charge get their act together and abolish it...

Re:Kill DST instead!!!! (1)

NotBornYesterday (1093817) | more than 5 years ago | (#24927497)

Why does your blanket have feet on it? And why are you cutting them off?

Re:Kill DST instead!!!! (1)

toddestan (632714) | more than 5 years ago | (#24927173)

Why don't you ask if you can come into work earlier so that you can leave earlier, rather than messing with my clock?

Re:Kill DST instead!!!! (1)

nsayer (86181) | more than 5 years ago | (#24927377)

Because maybe he's a bus driver and flex time wouldn't work very well.

Re:Kill DST instead!!!! (1)

mrsquid0 (1335303) | more than 5 years ago | (#24927209)

> Think of how many lives daylight savings saves regarding traffic Actually, that is a myth. To make matters worse, what little affect there is on traffic safety depends on what side of the time zone that one is on, so the tiny benefit gained in cities on one edge is balanced by the cities on the other edge. The reality is that DST has far more effect on one shopping habits than it does on safety. DST is just another example of social engineering. Now, that said, it is nice to have a few hours of daylight in the evening. However, I would prefer to have that extra light in the morning, when I am trying to wake up, rather than when I am trying to go to sleep.

Re:Kill DST instead!!!! (1)

nsayer (86181) | more than 5 years ago | (#24927321)

Think of how many lives daylight savings saves regarding traffic

Um, if you extend DST longer, then you're going to lose all those lives you save by having the morning commute occur in darkness.

They tried this during WWII. It was called "War Time," and yes, the accident rate went up in the mornings during the winter.

You and me both! (4, Funny)

BitterOldGUy (1330491) | more than 5 years ago | (#24926839)

I'd be more interested in killing Daylight Savings Time than dealing with Leap Year.

My cat wakes me up in the morning. She doesn't adjust. Because of her, I'm a morning person. Unfortunately, 90% of society are night people. Meaning, any social activity is past my bedtime and I become a wet blanket because I start yawning at everything at 20:00.

Re:You and me both! (5, Funny)

Anonymous Coward | more than 5 years ago | (#24926929)

I think your REAL problems are as follows:

You have a cat.

Your cat controls you.

You characterize and categorize people (90%, society, night people) in terms of what they can give you (social activity).

You speak in military (24 hour) time unnecessarily.

You admit your own faults, but rather than fix them, you prefer to revel in your own meekness.

Re:You and me both! (5, Funny)

BitterOldGUy (1330491) | more than 5 years ago | (#24927241)

I think your REAL problems are as follows:

You have a cat.

Your cat controls you.

You characterize and categorize people (90%, society, night people) in terms of what they can give you (social activity).

You speak in military (24 hour) time unnecessarily.

You admit your own faults, but rather than fix them, you prefer to revel in your own meekness.

Dogs have masters.

Cats have servants.

I recognize my overlord and serve her. And as a result, my life is filled with a wondrous furry glory!

The Egyptians worshiped cats as gods and the cats have never forgotten that.

Military time is also computer server time. And if you deal with computers across at least one time zone you may want to use Zulu time too. Oooooo, I used another military term. You know why!? Because, I serve in the army of cats!

Re:You and me both! (cat clock adjustments) (1)

WillAffleckUW (858324) | more than 5 years ago | (#24926935)

My cat wakes me up in the morning. She doesn't adjust. Because of her, I'm a morning person.

Try not feeding her - I think you'll find she'll wake you up a lot earlier ...

Re:You and me both! (cat clock adjustments) (1, Funny)

Anonymous Coward | more than 5 years ago | (#24927043)

or that she won't wake you up at all!

Re:You and me both! (cat clock adjustments) (0)

Anonymous Coward | more than 5 years ago | (#24927187)

Depends on how you train them. My cat is on a special diet and gets fed at exactly the same time every day and has a very limited amount of food. She also gets screwed up with daylight savings time, HOWEVER she has learned that she doesn't get fed when I'm sleeping and if she wakes me up then she's getting a pillow/shoe/whatever to the head. She learned not to wake me up real quick.

Once I'm awake it's a different story though, so annoying. I wish she could tell time so she wouldn't bug me for the hour or so beforehand.

Re:You and me both! (1)

fm6 (162816) | more than 5 years ago | (#24927233)

And in fact people who work with animals are the biggest opponents of DST. Their livestock refuses to change its habits just because clock time has changed.

What, you say you don't work with animals? Yes you do. You're a cat servant.

Re:Kill DST instead!!!! (5, Insightful)

Kjella (173770) | more than 5 years ago | (#24927035)

Killing it? I want to change them completely, and wintertime too. Now, I live a bit further north than most people (60 degrees latitude) and what happens in the winter is that I, like most people, head to work in the dark and come home in the dark. Maybe you get to see some sun on your lunch break, but unless you got an office with a view you won't see much of it otherwise. If we have like 6 hours of sun, they should be 4PM-10PM so you can do some outdoor activity after work. What happens now is I sit indoors during the day because of work, and I sit indoors in the evenings because it's dark and cold outside. I haven't got any stats to back it up but I'd think most people work indoors these days, the reason to have light == noon so you could run around outside just isn't there. I'd be happy with mornings that suck (some more) and evenings that were bright and nice all year round.

Re:Kill DST instead!!!! (1)

corsec67 (627446) | more than 5 years ago | (#24927275)

Why not see if you could get to work at (say) midnight, so that when you get home it is morning?

How about instead of redefining time, you change what the times mean?

That is my complaint about DST: instead of leaving it up to businesses to start work at 9 instead of 8, they have to mandate that the whole concept of local time changes.

Re:Kill DST instead!!!! (1)

Kjella (173770) | more than 5 years ago | (#24927503)

Why not see if you could get to work at (say) midnight, so that when you get home it is morning?

It's not the "getting to work" part, it's the "staying employed" part. Very few jobs, even with flexible hours will accept that you're never around during normal business hours. And the whole bit about social events which would then happen at "nighttime" for you.

That is my complaint about DST: instead of leaving it up to businesses to start work at 9 instead of 8, they have to mandate that the whole concept of local time changes.

It's not like they're warping the time stream or anything, it's just digits on a watch and there's no law saying businesses can't "un-DST" their business hours. Can it be that what you really have a problem with is being an hour out of synch with everybody else? In that case it's rather funny because it's exactly what you suggest for me, while trying to avoid it yourself by trying to remove DST rather than just live on non-DST time if that's what you want.

Re:Kill DST instead!!!! (1)

Jorophose (1062218) | more than 5 years ago | (#24927383)

But think of the children!

No, really.

How the hell am I going to go to sleep and wake up in time?

3PM-9PM, with the sun completely down at 10PM would be pretty sweet. I mean, I'm in school all day, and they're leaving the lights on anyway, so why not? I finish school and it's bright out, it's so great to go outside! It would encourage us to get off our fat asses too. No more excuses. It's now sunny outside when you don't have work.

Re:Kill DST instead!!!! (1)

Mr. Slippery (47854) | more than 5 years ago | (#24927165)

I'd be more interested in killing Daylight Savings Time than dealing with Leap Year.

Feh. You can have my daylight savings time when you pry it from my cold dead hand.

Want a powerful life that you love? Try Landmark Education

If you're going to join a cult that uses lawyer and the DCMA to silence critics [apologeticsindex.org] , why not go all the way for Scientology?

Re:Kill DST instead!!!! (1)

zappepcs (820751) | more than 5 years ago | (#24927251)

Yes, indeed. I was hoping to find an explanation in comments... I don't have TIME to read the articles... sigh

Automated and consistent leap seconds (1)

syousef (465911) | more than 5 years ago | (#24926861)

This adding of leap seconds based on decisions by panels of experts or authoritative bodies is a nonsense.

If you're going to do this sort of thing - adding seconds to the clock here or there - it shouldn't be decided upon by some review committee. There should be a planned algorithm that kicks in, and the simplest one that actually does the job should be used. The bottom line is that a watch should be able to do it. If you do this, you're able to program devices to account for leap seconds instead of having to manually put in fudges which is an error prone process. You also get the possibility of adding leap milli-seconds or micro-seconds so fine grained adjustments are possible where required, whereas it would be much harder (though not impossible) to do that if you're manually correcting.

I'd be interested in hearing about specific instances where people work with equipment where this is a concern. I don't think I even own a time keep device where this level of accuracy matters. Perhaps my GPS???...

Re:Automated and consistent leap seconds (5, Insightful)

klapaucjusz (1167407) | more than 5 years ago | (#24926991)

There should be a planned algorithm that kicks in,

This assumes that we know when, in the future, we'll need to insert leap seconds. And we don't.

Leap seconds are introduced in order to compensate for medium-term variations in the earth's rotation speed. We don't have a good understanding of the way the earth rotates -- knowing what UTC time it will be in ten years' time is about as difficult as predicting the weather for next week-end.

Re:Automated and consistent leap seconds (1)

Ron Bennett (14590) | more than 5 years ago | (#24926997)

The Earth's rotation varies somewhat unpredictably and thus there's no simple way of automatically adding/subtracting leap seconds without observation first.

Communications, such as cellular phone networks, often depend on very precise syncronized timing.

Ron

Re:Automated and consistent leap seconds (2, Interesting)

surmak (1238244) | more than 5 years ago | (#24927045)

If you're going to do this sort of thing - adding seconds to the clock here or there - it shouldn't be decided upon by some review committee. There should be a planned algorithm that kicks in, and the simplest one that actually does the job should be used. The bottom line is that a watch should be able to do it. If you do this, you're able to program devices to account for leap seconds instead of having to manually put in fudges which is an error prone process. You also get the possibility of adding leap milli-seconds or micro-seconds so fine grained adjustments are possible where required, whereas it would be much harder (though not impossible) to do that if you're manually correcting.

It cannot be done. Leap seconds are dependent on unpredictable, chaotic natural events -- namely the fact that one day in not exactly 24 hours in length. The daily error is not constant, so the only way to determine when a leap second is required is through astronomical observations.

Re:Automated and consistent leap seconds (4, Informative)

John Hasler (414242) | more than 5 years ago | (#24927075)

> There should be a planned algorithm that kicks in, and the simplest one that actually
> does the job should be used.

There is none. The rate of rotation of the Earth is slightly irregular in a not entirely predictable way.

> I don't think I even own a time keep device where this level of accuracy matters.
> Perhaps my GPS?

Definitely your GPS. It cares about nanoseconds.

Re:Automated and consistent leap seconds (0)

Anonymous Coward | more than 5 years ago | (#24927405)

Wikipedia! [wikipedia.org] (emphasis mine):

Leap seconds are necessary because time is measured using stable atomic clocks (TAI or International Atomic Time), whereas the rotation of Earth slows down continually, though at a slightly variable rate. [...] The actual rotational period varies due to unpredictable factors such as the motion of mass within Earth, and has to be observed rather than computed.

No leap seconds prior to Jan. 20, 2009 please (4, Funny)

jayveekay (735967) | more than 5 years ago | (#24926893)

We don't need even one more second of Bush presidency. :)

LOLOLOLOLOMG!!!!!!!11111 (0)

Anonymous Coward | more than 5 years ago | (#24927169)

Congress' approval rating since Do-Nothing Nancy took over has consistently been about 1/3 that of George Bush's. But I guess you'd actually have to pay attention to politics instead of sniping from the sidelines during American Idol commercial breaks.

Re:LOLOLOLOLOMG!!!!!!!11111 (1)

justinlee37 (993373) | more than 5 years ago | (#24927201)

So his opinion is wrong because it doesn't conform to the majority? I think you might be the one watching too much American Idol.

The sun is overhead at noon? (0)

Anonymous Coward | more than 5 years ago | (#24926901)

Ohhhh.....in my world the sun is RARELY directly overhead at noon... not by the common definition of noon that all watches, cell phones, computers, media, etc. etc. use but by astronomers definition of noon. However isn't that the definition of "noon" when the sun is overhead?
I just wish we could get rid of Daylight Saving Time
The twice-yearly stupid time shift is just retarded. I think we should shift our schedules to fit daylight, not the other way around.

Lets define the daily "work period" as: "three hours after sunrise to three hours before sunrise". And yes, I realize that in Winter, I'll be working a four-hour day and in the summer, I'll be working a twelve-hour day. But it's my idea and I like it.

Re:The sun is overhead at noon? (1)

sexconker (1179573) | more than 5 years ago | (#24926969)

You enjoy those 18-hour workdays, do you?

So long as we don't have leap nanoseconds (0, Troll)

WillAffleckUW (858324) | more than 5 years ago | (#24926911)

I fail to see why there's any urgency to decide this, as we don't have leap nanoseconds or even leap milliseconds.

I set my non-existent watch by the solar-powered parking meters along the street, actually.

And why are we still keeping to a 60 second or 60 minute clock anyway?

Re:So long as we don't have leap nanoseconds (2, Insightful)

Martin Blank (154261) | more than 5 years ago | (#24927223)

Changing the length of a second will end up changing almost everything in our lives. It would be an enormous undertaking, redefining, among many other things, electromagnetic wavelengths and the speed of light. Speed limits would change, computers would have to handle travel time calculations differently, and the length of the workday would change slightly.

It was hard enough to get the world to change to the metric system (with notable holdouts still remaining). Changing the very definition of one of the six core SI units would be nearly impossible.

Re:So long as we don't have leap nanoseconds (0)

Anonymous Coward | more than 5 years ago | (#24927347)

And we would just have to keep doing it over and over and over...

Re:So long as we don't have leap nanoseconds (1, Troll)

WillAffleckUW (858324) | more than 5 years ago | (#24927471)

I didn't mean to alter the actual measurement of time per se - e.g. as the world slows or speeds we adjust the length of a second.

What I meant was that, in actual fact, there should be leap nanoseconds and atomic clocks handle those adjustments, but we don't record them per se.

As to changing time, the Sumerians didn't even agree as to the precise definition, and many cultures have accurately kept time using wheels and water clocks using other measurements - China, Aztecs, Toltecs, etc.

We really only keep clock seconds - changing the names of the units above it shouldn't matter.

Besides, humans have a natural 25 hour clock, so it seems the earth may have rotated much faster originally, so our current "hours" are probably not correct.

Why not just change time pieces to include the (1)

BitterOldGUy (1330491) | more than 5 years ago | (#24926913)

increasing time?

Yeah, I guess the clocks would have to take into account the increases in orbits and whatnot mentioned, but so what? Computation has become dirt cheap. So the Naval Observatory does an extra calculation for GPS and things that require that kind of accuracy.

And as far as I'm concerned, my clocks are all within 10 minutes of each other - in other words, I don't give a shit about 10 minutes either way.

Re:Why not just change time pieces to include the (1)

klapaucjusz (1167407) | more than 5 years ago | (#24927123)

I don't give a shit about 10 minutes either way.

It depends on the application. Having one's NFS file server just a second fast will break most Makefiles.

Re:Why not just change time pieces to include the (2, Funny)

robo_mojo (997193) | more than 5 years ago | (#24927291)

It depends on the application. Having one's NFS file server just a second fast will break most Makefiles.

I think that says more about make than it says about timekeeping.

Re:Why not just change time pieces to include the (1)

multipartmixed (163409) | more than 5 years ago | (#24927355)

Nah. It just gets bitchy. "Blah blah has modification time in the future!"

You might wind up generating a couple of .o files more than you need to, but I wouldn't call that breakage.

Now, an NFS server that's running SLOW, OTOH....

Re:Why not just change time pieces to include the (4, Informative)

rrohbeck (944847) | more than 5 years ago | (#24927509)

That's exactly the point. Changing software in military or even space systems isn't exactly trivial, maybe not even possible, plus you need a method to constantly provide (UT1-UTC) to the systems that rely on UT1 (astronomical time) being equal to UTC by less than a second. Like the radio controlled clock in your home. Or the time signal transmitters would have to be redefined not to transmit UTC but some new time scale, which would be a mess for GPS.

UTC without leap seconds is basically TAI (international atomic time) - a strictly linear SI second timescale as precise as we can reproduce it.
Just distribute (TAI-UTC) and (UT1-UTC) together with the usual time signals, leave UTC alone (with leap seconds) and you're all set and can use what you need. There is no one time scale; Einstein told us so. Better accept it.

Americans are (1, Funny)

JustOK (667959) | more than 5 years ago | (#24926941)

too lazy to deal with anything that even sounds like physical exertion unless they have a multi-million dollar contract.

Uhh (0)

Anonymous Coward | more than 5 years ago | (#24926999)

there is a demonstrated way to respect the history, remove leaps from navigation and POSIX time, yet keep the sun overhead at noon.

If having the sun overhead at noon is a concern, the intentional inaccuracy of an hour might be the first thing to fix instead of a leap second.

Explain the Article? (0)

Anonymous Coward | more than 5 years ago | (#24927025)

Kdawson, I tried to read the article, but I was confused. In the future, can you post a link to explain what TCB, TCG, TDB, TDT, TT, ET, TAI, UT1, and UTC are? And what is the proleptic TT and proleptic TCG?

But I must admit that I'm very impressed. The fact that kdawson was able to read and understand this article before approving it means that he (or she) is much smarter than I thought.

Re:Explain the Article? (1, Funny)

Anonymous Coward | more than 5 years ago | (#24927091)

"The fact that kdawson was able to read and understand this article..."

You must really be new around here.

quick fix (1)

floatingrunner (621481) | more than 5 years ago | (#24927049)

adjust the orbit of the Eart, just axe people in China and India all jump at the same time

I know! (4, Funny)

tnk1 (899206) | more than 5 years ago | (#24927225)

Let's just remove the problem entirely!

I suggest... the French Republican calendar.

And a good Tridi, 23 Fructidor, Year 216 to you too.

Shakespeare was first (1)

andreyvul (1176115) | more than 5 years ago | (#24927237)

"to leap or not to leap"
Time scales Prince Hamlet make.

superman could help (2, Funny)

Tr3vin (1220548) | more than 5 years ago | (#24927243)

Why don't we just get Superman to fly around the Earth really fast to slightly change its rotation. If he can reverse time, surely he could adjust it sightly so that everything would work out.

Why is this the DoD's responsibility? (2, Funny)

k1e0x (1040314) | more than 5 years ago | (#24927283)

I don't understand what the DoD has to do with time, standards or measurements.

Is the DoD trying to say now Muhahaha! Now we control time itself, submit all ye to "civilian time"?

We need to get the opinion of an expert, not some random poll.. perhaps the DoD should seek the advice of the master of timecube theory Dr. Gene Ray.

Re:Why is this the DoD's responsibility? (1)

multipartmixed (163409) | more than 5 years ago | (#24927379)

I think you've got the wrong DoD here.

The Denizens of Doom are trying to control time, because indirectly, time controls doppler RADAR.

Who cares about all this timezone crap? (1, Interesting)

Dogun (7502) | more than 5 years ago | (#24927339)

Who gives a damn about the sun being overhead at 12PM? China operates in a single timezone, despite spanning something like five, and they do just fine.

Give us GMT. Let noon drift where noon drifts. Just keep the seasons in line with the longest and shortest days and forget the rest.

i propose... (0)

Anonymous Coward | more than 5 years ago | (#24927415)

...just redoing the calendar correctly. metric maybe? like with only 10 months, or maybe 100 months. one day could be a milliyear. (we've come a long way technologically since they came up with the current calendar, it's time to get with the program.)

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?
or Connect with...

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>