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'Leap Second' to Be Added on New Year's Eve This Year

'Leap Second' to Be Added on New Year's Eve This Year

Full story: <http://www.space.com/33361-leap-second-2016-atomic-clocks.html>

  Revelers will get to celebrate New Year's Eve for a tiny bit longer 
than usual this year.

A "leap second" will be added to the world's official clocks on Dec. 31 
at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC), 
which corresponds to 6:59:59 p.m. EST; the clocks will read 23:59:60 
before ticking over to midnight. The goal is to keep two different 
timescales in sync with each other.

The units of time had long been defined based on Earth's rotation 
relative to distant celestial bodies. But that changed with the 
invention of atomic clocks in the mid-20th century; scientists then 
decided to base the second on the natural vibrations of the cesium atom. 
[How to Build the Most Accurate Atomic Clocks (Video)]

These two timescales don't match up exactly, however. Measurements show 
that, because the moon's gravitational pull and other factors are 
gradually slowing Earth's spin, the rotation-based scale loses between 
1.5 and 2 milliseconds per day compared to atomic time — meaning the two 
diverge by a full second every 500 to 750 days.

Leap seconds are a way to make up for this difference. Since 1972, the 
International Earth Rotation and Reference Systems Service (IERS) — the 
organization that keeps track of time for the world — has added 26 leap 
seconds to atomic clocks, with the last such insertion coming on June 
30, 2015.

  The aim is to keep the two timescales within 0.9 seconds of each other.

"We can easily change the time of an atomic clock, but it is not 
possible to alter the Earth's rotational speed to match the atomic 
clocks," officials with the U.S. Naval Observatory (USNO), which 
maintains the Department of Defense's master clock, noted — wryly, it 
would seem — in a statement today (July 6).

While Earth's rotation rate is slowing, the effect is quite subtle.

"Confusion sometimes arises over the misconception that the occasional 
insertion of leap seconds every few years indicates that the Earth 
should stop rotating within a few millennia," USNO officials wrote. 
"This is because some [people] mistake leap seconds to be a measure of 
the rate at which the Earth is slowing. The 1-second increments are, 
however, indications of the accumulated difference in time between the 
two systems."

When leap seconds are added, they are always inserted on June 30 or Dec. 
31 of a particular year. In 1972, IERS officials called for a leap 
second to be inserted on both dates.
0
Mr
12/22/2016 1:43:58 PM
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In article <o3gl85$j26$1@dont-email.me>,
 "Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:

> 'Leap Second' to Be Added on New Year's Eve This Year

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!

2016 has lasted long enough! NOT ONE SECOND LONGER!

-- 
:-<> Siri Seal of Disavowal #000-001. Disavowed. Denied. Deleted.
'I desire mercy, not sacrifice.'
Free the Amos Yee one.
Yeah, too bad about your so-called life. Ha-ha.
0
Siri
12/22/2016 1:48:36 PM
On 22/12/2016 9:48 PM, Siri Cruise wrote:
>> 'Leap Second' to Be Added on New Year's Eve This Year
>
> NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!
>
> 2016 has lasted long enough! NOT ONE SECOND LONGER!
>

Would this event hurt all installed Windows 10? :)
0
Mr
12/22/2016 2:09:52 PM
On 12/22/2016 07:43 AM, Mr. Man-wai Chang wrote:
> 'Leap Second' to Be Added on New Year's Eve This Year
>
> Full story:
> <http://www.space.com/33361-leap-second-2016-atomic-clocks.html>
>
>  Revelers will get to celebrate New Year's Eve for a tiny bit longer
> than usual this year.
>
> A "leap second" will be added to the world's official clocks on Dec. 31
> at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC),
> which corresponds to 6:59:59 p.m. EST; the clocks will read 23:59:60
> before ticking over to midnight. The goal is to keep two different
> timescales in sync with each other.

[snip]

It you're watching your computer's clock approaching UTC midnight, what 
should you expect to see? Would there be a 23:59:60, or would 23:59:59 
last for 2 seconds instead of one? I've heard its the latter, but am not 
sure.

BTW, I'm in central time, so global midnight is at 6PM.

-- 
3 days until the winter celebration (Sunday December 25, 2016 12:00:00
AM for 1 day).

Mark Lloyd
http://notstupid.us/

"To talk intelligibly about modern physics, we have to admit the
possibility of uncaused events." Taner Edis, Is Anybody Out There?
0
Mark
12/22/2016 8:31:27 PM
In article <o3gl85$j26$1@dont-email.me>, toylet.toylet@gmail.com says...
> A "leap second" will be added to the world's official clocks on Dec. 31 
> at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC), 
> 

Google has an interesting approach to this to make sure that the 1-
second adjustment doesn't cause problems. They "smear" the change over a 
longer period of time: 

https://googleblog.blogspot.com/2011/09/time-technology-and-leaping-
seconds.html
0
Jason
12/22/2016 10:14:07 PM
On Thursday, December 22, 2016 at 5:14:15 PM UTC-5, Jason wrote:
> In article <o3gl85$j26$1@dont-email.me>, toylet.toylet@gmail.com says...
> > A "leap second" will be added to the world's official clocks on Dec. 31 
> > at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC), 
> > 
> 
> Google has an interesting approach to this to make sure that the 1-
> second adjustment doesn't cause problems. They "smear" the change over a 
> longer period of time: 
> 
> https://googleblog.blogspot.com/2011/09/time-technology-and-leaping-
> seconds.html

With all of the digital technology we have these days, and with people
relying on their computers and phones for the time, why can't our society
smear the daylight savings hour over a long period of time so our days
are just constantly reflecting accurately our target daylight portion?

Best regards,
Rick C. Hodgin
0
Rick
12/22/2016 10:38:39 PM
Jason wrote:
> In article <o3gl85$j26$1@dont-email.me>, toylet.toylet@gmail.com says...
>> A "leap second" will be added to the world's official clocks on Dec. 31 
>> at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC), 
>>
> 
> Google has an interesting approach to this to make sure that the 1-
> second adjustment doesn't cause problems. They "smear" the change over a 
> longer period of time: 
> 
> https://googleblog.blogspot.com/2011/09/time-technology-and-leaping-
> seconds.html
> 

Neat idea. Although most services can handle a 1-second blip. One
sensitive service is mail servers. Old dovecot v1.x did not handle
discrepancies well, but only when time "goes backwards" and for more and
one second. Took several second offset and the server would crash and
need to restart the service.

-- 
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com
0
Jonathan
12/22/2016 10:40:35 PM
In article <zKW6A.231838$Uz2.141850@fx29.iad>,
 Mark Lloyd <not@mail.invalid> wrote:

> On 12/22/2016 07:43 AM, Mr. Man-wai Chang wrote:
> > 'Leap Second' to Be Added on New Year's Eve This Year
> >
> > Full story:
> > <http://www.space.com/33361-leap-second-2016-atomic-clocks.html>
> >
> >  Revelers will get to celebrate New Year's Eve for a tiny bit longer
> > than usual this year.
> >
> > A "leap second" will be added to the world's official clocks on Dec. 31
> > at 23 hours, 59 minutes and 59 seconds Coordinated Universal Time (UTC),
> > which corresponds to 6:59:59 p.m. EST; the clocks will read 23:59:60
> > before ticking over to midnight. The goal is to keep two different
> > timescales in sync with each other.
> 
> [snip]
> 
> It you're watching your computer's clock approaching UTC midnight, what 
> should you expect to see? Would there be a 23:59:60, or would 23:59:59 
> last for 2 seconds instead of one? I've heard its the latter, but am not 
> sure.
> 
> BTW, I'm in central time, so global midnight is at 6PM.

Your computers clock doesn't know anything about the leap second, so it 
will tick over at midnight New Years just as it does every other night. 
When it next connects to a time server it will simply update itself to 
the correct time as it always does. However, the official NIST clocks 
will, as I understand it, go to 23:59:60.

I guess if you live in the GMT time zone, you'll need to throw an extra 
'1' into the countdown before cheering and throwing streamers.
0
Mark
12/23/2016 2:34:11 PM
Le 23/12/2016 � 15:34, Mark Storkamp a �crit :
>  However, the official NIST clocks 
> will, as I understand it, go to 23:59:60.
Yes, and that's why Calendar had such a hard time dealing with leap
seconds without raising Constraint_Error...

-- 
J-P. Rosen
Adalog
2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX
Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00
http://www.adalog.fr
0
J
12/23/2016 3:55:53 PM
On Thu, 22 Dec 2016 17:40:35 -0500 "Jonathan N. Little" 
<lws4art@gmail.com> wrote in article <o3hkmg$e6m$1@dont-email.me>
> Neat idea. Although most services can handle a 1-second blip.
> 

Google reported that there is some kind of lock required with multiple 
servers that can't handle the sudden 1-second change. That's what 
motivated them to adopt the smearing scheme.
0
Jason
12/24/2016 12:57:25 AM
On Fri, 23 Dec 2016 19:57:25 -0500, Jason <jason_warren@ieee.org> wrote:

>On Thu, 22 Dec 2016 17:40:35 -0500 "Jonathan N. Little" 
><lws4art@gmail.com> wrote in article <o3hkmg$e6m$1@dont-email.me>
>> Neat idea. Although most services can handle a 1-second blip.
>> 
>
>Google reported that there is some kind of lock required with multiple 
>servers that can't handle the sudden 1-second change. That's what 
>motivated them to adopt the smearing scheme.

For the networking gear that has an issue dealing with leap seconds,
it's not the leap second itself that causes problems. It's the *notice*
that a leap second is coming. Certain NTP clients totally choke when
they get that flag. It doesn't seem like it would be a big deal, but
it's a big deal, indeed. That's why leap smearing avoids the problem.
With smearing, there's no flag.

0
Char
12/24/2016 3:44:36 AM
On 22 Dec 2016, Siri Cruise wrote
(in article<chine.bleu-C58C6A.05482722122016@news.eternal-september.org>):

> In article<o3gl85$j26$1@dont-email.me>,
> "Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:
> 
> > 'Leap Second' to Be Added on New Year's Eve This Year
> 
> NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!
> 
> 2016 has lasted long enough! NOT ONE SECOND LONGER!

On the plus side, one second longer sleep/new year party.

-- 
Popularize the elitism!

0
Krzysztof
12/24/2016 12:47:43 PM
In article <0001HW.1E0EA5EF0116D04B7000024503BF@nntp.idecnet.com>,
 Krzysztof Mitko <invalid@kmitko.at.list.dot.pl> wrote:

> On 22 Dec 2016, Siri Cruise wrote
> (in article<chine.bleu-C58C6A.05482722122016@news.eternal-september.org>):
> 
> > In article<o3gl85$j26$1@dont-email.me>,
> > "Mr. Man-wai Chang" <toylet.toylet@gmail.com> wrote:
> > 
> > > 'Leap Second' to Be Added on New Year's Eve This Year
> > 
> > NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!
> > 
> > 2016 has lasted long enough! NOT ONE SECOND LONGER!
> 
> On the plus side, one second longer sleep/new year party.

Isn't bad enough that US presidential election years are longer by one full day 
(29 Feb)? Not one more second!

-- 
:-<> Siri Seal of Disavowal #000-001. Disavowed. Denied. Deleted.
'I desire mercy, not sacrifice.'
Free the Amos Yee one.
Yeah, too bad about your so-called life. Ha-ha.
0
Siri
12/24/2016 1:39:21 PM
Reply: