Posted by
timothy
on from the seconds-all-taste-the-same dept.
ygslash writes "The IERS has announced today that, after seven years, there will once again be a leap second this year. On December 31, 2005, the time 12:59 will last for 61 seconds."
Star Trek has it figured out.
by
Goalie_Ca
·
· Score: 3, Funny
Stardates
The only problem is that no one knows how its supposed to work.
--
----
Go canucks, habs, and sens!
Re:Star Trek has it figured out.
by
toddbu
·
· Score: 4, Interesting
The only problem is that no one knows how its supposed to work.
They work much like warp speed - start out low and end high. The higher the epsiode number, the higher the range. I think that it's derived from fishing, where "the big one that got away" gets bigger each time the story is told.
-- If you don't want crime to pay, let the government run it.
Re:Shouldn't that be...
by
dextr0us
·
· Score: 4, Informative
A positive leap second will be introduced at the end of December 2005.
The sequence of dates of the UTC second markers will be:
2005 December 31, 23h 59m 59s 2005 December 31, 23h 59m 60s 2006 January 1, 0h 0m 0s
Actually, its 12:00:00 then another 12:00:00.
-- "Martha Stewart can lick my Scrotum......do i have a scrotum?" -- Sharon Osbourne
I've always wanted a timeslip (i.e. from the Mars Trilogy)
-- Real_men_don't_need_spacebars.
Re:Should we really bother?
by
B.D.Mills
·
· Score: 5, Interesting
It depends on your definition of "significant".
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
On the other hand, in 1 million years, about 15 leap seconds will be required each day. Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds. We would have a situation where the record for the 100 metres dash is expressed in seconds, but the length of the second used for dividing up the day is not the same length. Such "stretched time" has already been used for the Spirit and Opportunity rovers on Mars.
[1] A common formula for approximating the evolution of delta-T over time is 31 * Cy^2, where Cy is expressed in centuries.
--
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
Its always bugged me how...
by
IronMagnus
·
· Score: 3, Interesting
Its always bugged me how in a leap year, we have an extra day... but a leap second is an entire extra second... if the terminology were consistent, that would mean a leap yer would equal one extra year.. or that a leap second was some fraction of a second longer than a normal one.
Re:I have an atomic watch!
by
interweb
·
· Score: 2, Funny
"To authorities responsible for the measurement and distribution of time..." How do I make an official complaint with these time-distributing authorities for all the times I've been blamed for being late? Everyone always thought it was my fault for running out of time--but nope, turns out there are "authorities" in charge of all that. Are they any relation to the Tooth Fairy?
Two questions
by
roystgnr
·
· Score: 2, Insightful
Isn't this sort of thing calculable farther in advance? There shouldn't be a whole lot of angular momentum being added or subtracted from the Earth's rotation.
Do I need a new glibc? Or any other POSIX library, for that matter? If this is a new announcement then presumably every implementation of mktime(), localtime(), gmtime(), etc. needs to be updated.
Re:Two questions
by
lachlan76
·
· Score: 2, Insightful
Actually you'd just set the NTP server you're syncing with one second ahead. I don't think that a once-every-seven-year event is going to be worthy of kernel changes, especially since your time is probably off by more than one second as it is.
Re:Two questions
by
Mudd+Guy
·
· Score: 5, Informative
Actually, it's not calculable farther in advance. The Earth's rotation is inconsistent enough that leap seconds are sometimes needed, but the need can't be predicted more than about a year in advance [1]. In other words, there is noise in the Earth's rotation period of about 1 second per year. Atomic clocks are a lot better than this (good to ~50 ns per year [2]!!!), so it's pretty easy to detect the problem.
According to a link I just read, POSIX doesn't handle leap seconds. So yes, if you use NTP, like someone else suggested, your time will be correct, but any measurements of time crossing leap seconds won't.
The correct solution in my opinion would be to store leap seconds along with the timezone information. That's really what they are. Unix time could be stored in TAI instead of UTC, and thus subtracting two times from each other would still give the correct result.
Whenever a leap second was announced you'd have to download a new timezone file, and if you didn't download the file in time your displayed time would be off by a second. Alternatively, if you synced using NTP, which is in UTC, and you didn't update your timezone file, then your computer would incorrectly slow down the clock by one second. Once you installed the timezone file, and resynced with NTP, this would be corrected.
Eventually NTP should probably be switched over to TAI. I see a proposal for this in a mailing list in January 2004. Would have been nice to do it before the leap second, but that's probably too soon to expect many people to change at this point.
Off by one error
by
Taral
·
· Score: 3, Interesting
Oh, joy. Everyone'll be off a second on the damn New Year's count... again!
-- Taral
WARN_(accel)("msg null; should hang here to be win compatible\n");
-- WINE source code
Re:Off by one error
by
anthony_dipierro
·
· Score: 3, Insightful
Seriously, you'd think they'd pick a less conspicuous second to make the switch. Instead they picked the one second of the year that people notice more than any other. At least it'll only affect the New Year's count for the Brits. Here in the US we won't even be heading to the party yet.
Re:Should we really bother?
by
Unordained
·
· Score: 3, Interesting
Not so many centuries ago, the concept of 'hour' was flexible, depending on the season. 12 day hours, 12 night hours, regardless of the ratio between them. Back to the old?
Re:These guys must not be real nerds
by
Everleet
·
· Score: 2, Funny
Each minute that is a multiple of 3 shall last 42 seconds, and each minute that is not shall last 69 seconds. It's the perfect system.
-- It's tragic. Laugh.
A standardized second.
by
TapeCutter
·
· Score: 2, Funny
The same uber-nerds who defined the meter have also defined the second.
Lifted from wikipedia - The second is one of seven SI base units. It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at zero kelvins.
Now that we have a definition perhaps someone could tell us what it means.:)
-- And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Re:A standardized second.
by
J'raxis
·
· Score: 2, Informative
All it means is that someone looked at the conventional length of a second (1/86400 of a day) and found a natural phenomena that was really, really, really, really, really close, and unlike the length of a day, won't change over time.
As another example, take the metre. You can see how the definition of the metre became more and more precise here. I don't see it mentioned there, but the original "meaningful" definition of the metre, if extremely imprecise, is based on water: 1 ml of water = 1 gm in mass = 1 cm on each side when formed intoa cube.
Re:Should we really bother?
by
antispam_ben
·
· Score: 2, Interesting
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
Simple solution, change the 60 Hz power line frequency to 59.9999885922 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
On the other hand, in 1 million years, about 15 leap seconds will be required each day.
Simple solution, change the 59.9999885922 Hz power line frequency to 59.9895833333 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds.
More seriously, I can see where all watches (except the old-fashioned mechanical ones rich people have) will be synchronized to whichever standard the wearer specifies, receiving and converting from an absolote standard such as WWVB as "atomic clocks" do now. Most people will use the daily rotation of the Earth (as referenced to the Sun) standard, but perhaps the stopwatch function can use the "historically established" value for the duration of a second.
Having a watch that keeps several times with good accuracy and converts between them is not a problem now. There are several easily available low-power microcontrollers that will give reasonable battery life. To quote bad sci-fi, "We have the technology."
-- Tag lost or not installed.
Re:These guys must not be real nerds
by
VernonNemitz
·
· Score: 4, Interesting
The thing that bothers me is, when that big quake in Indonesia went off last year and caused that big tsunami, they talked about how the Earth's rotation SPEEDED UP. If it has already slowed down again in only one year, such that a leap second is needed, then that implies some other place has been bulging and may be about to give way. So, any Slashdotters who can pass this inference on to the geology folks, please do so pronto! Thanks!
Re:Shouldn't that be...
by
pmc
·
· Score: 2, Informative
Arrrrhhh! No.
0h 0m 0s = Midnight 12h 0m 0s = Noon.
These is no such time as 12:00:00am (or 12:00:00pm).
Microsoft has $33.8 billion in short term investments. Since interest payments are calculated by the day, and not the second, at an interest rate of 3% Microsoft will lose $1929 in interest due to this leap second.
Re:These guys must not be real nerds
by
Paradise+Pete
·
· Score: 2, Funny
59 / 3 = 19
I think you need a leap integer in there somewhere.
Slashdot Mirror
What AM I going to do with all that extra time?
Stardates
The only problem is that no one knows how its supposed to work.
----
Go canucks, habs, and sens!
A positive leap second will be introduced at the end of December 2005.
The sequence of dates of the UTC second markers will be:
2005 December 31, 23h 59m 59s
2005 December 31, 23h 59m 60s
2006 January 1, 0h 0m 0s
Actually, its 12:00:00 then another 12:00:00.
"Martha Stewart can lick my Scrotum......do i have a scrotum?" -- Sharon Osbourne
I've always wanted a timeslip (i.e. from the Mars Trilogy)
Real_men_don't_need_spacebars.
It depends on your definition of "significant".
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
On the other hand, in 1 million years, about 15 leap seconds will be required each day. Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds. We would have a situation where the record for the 100 metres dash is expressed in seconds, but the length of the second used for dividing up the day is not the same length. Such "stretched time" has already been used for the Spirit and Opportunity rovers on Mars.
[1] A common formula for approximating the evolution of delta-T over time is 31 * Cy^2, where Cy is expressed in centuries.
The only thing necessary for the triumph of evil is for good men to do nothing. - Edmund Burke
Its always bugged me how in a leap year, we have an extra day... but a leap second is an entire extra second... if the terminology were consistent, that would mean a leap yer would equal one extra year.. or that a leap second was some fraction of a second longer than a normal one.
What if the Sun goes out? How will you keep time?
From the IERS website:
Welcome to the International Earth Rotation and Reference Systems Service
Will they change my oil and check my brakes, too?
hah, my sun dial is also solar powered but doesn't need a radio reference.
"To authorities responsible for the measurement and distribution of time..." How do I make an official complaint with these time-distributing authorities for all the times I've been blamed for being late? Everyone always thought it was my fault for running out of time--but nope, turns out there are "authorities" in charge of all that. Are they any relation to the Tooth Fairy?
Isn't this sort of thing calculable farther in advance? There shouldn't be a whole lot of angular momentum being added or subtracted from the Earth's rotation.
Do I need a new glibc? Or any other POSIX library, for that matter? If this is a new announcement then presumably every implementation of mktime(), localtime(), gmtime(), etc. needs to be updated.
Oh, joy. Everyone'll be off a second on the damn New Year's count... again!
Taral
WARN_(accel)("msg null; should hang here to be win compatible\n");
-- WINE source code
Not so many centuries ago, the concept of 'hour' was flexible, depending on the season. 12 day hours, 12 night hours, regardless of the ratio between them. Back to the old?
This year's been bad enough for me, now it seems like it's going to drag on forever!
Actually, if they RTFA it's 11:59 PM... just wanted to clarify.
http://ablegray.com
I just wanted to be the first to mention this site, someone wanted to view the previous leap second, and that became an obsession.
Okay, here's a clickable link:
http://leapsecond.com/
An obsession in another are of time is this Y10K Compliant clock:
http://longnow.org/
Tag lost or not installed.
Each minute that is a multiple of 3 shall last 42 seconds, and each minute that is not shall last 69 seconds. It's the perfect system.
It's tragic. Laugh.
The same uber-nerds who defined the meter have also defined the second.
:)
Lifted from wikipedia - The second is one of seven SI base units. It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at zero kelvins.
Now that we have a definition perhaps someone could tell us what it means.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
I have calculated[1] that in 1000 years a leap second will be required about every two months. It's likely that at that time we would still be using time standards similar to those in use now.
Simple solution, change the 60 Hz power line frequency to 59.9999885922 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
On the other hand, in 1 million years, about 15 leap seconds will be required each day.
Simple solution, change the 59.9999885922 Hz power line frequency to 59.9895833333 Hz, causing power-line synchronous clocks to slow down to match the daily rotation of the Earth (as referenced to the Sun).
Therefore, at some point timekeeping must necessarily divide the day into units that are not an integral number of seconds.
More seriously, I can see where all watches (except the old-fashioned mechanical ones rich people have) will be synchronized to whichever standard the wearer specifies, receiving and converting from an absolote standard such as WWVB as "atomic clocks" do now. Most people will use the daily rotation of the Earth (as referenced to the Sun) standard, but perhaps the stopwatch function can use the "historically established" value for the duration of a second.
Having a watch that keeps several times with good accuracy and converts between them is not a problem now. There are several easily available low-power microcontrollers that will give reasonable battery life. To quote bad sci-fi, "We have the technology."
Tag lost or not installed.
The thing that bothers me is, when that big quake in Indonesia went off last year and caused that big tsunami, they talked about how the Earth's rotation SPEEDED UP. If it has already slowed down again in only one year, such that a leap second is needed, then that implies some other place has been bulging and may be about to give way. So, any Slashdotters who can pass this inference on to the geology folks, please do so pronto! Thanks!
Arrrrhhh! No.
0h 0m 0s = Midnight
12h 0m 0s = Noon.
These is no such time as 12:00:00am (or 12:00:00pm).
See NIST for the gory details.
Microsoft has $33.8 billion in short term investments. Since interest payments are calculated by the day, and not the second, at an interest rate of 3% Microsoft will lose $1929 in interest due to this leap second.
I think you need a leap integer in there somewhere.