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Leap Second At The End of 2005
Ruff_ilb writes "Because of the discrepency between an ephemeris second (the fraction 1/31,556,925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time) and the second of atomic time (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 cesium 133 atom), we're left with more than leap years. In order to ensure that the the atomic time and civil stay coordinated, "Civil time is occasionally adjusted by one second increments to ensure that the difference between a uniform time scale defined by atomic clocks does not differ from the Earth's rotational time by more than 0.9 seconds."" And Happy New Years everyone ;)
Most NTP servers use UTC time, so yes.
t - leap second bulletin
http://hpiers.obspm.fr/iers/bul/bulc/bulletinc.da
Video Production Support
So, as of today, any time stamp you have made using NTP, ever, has been retroactively displaced by one second. Intervals that included midnight (UTC) last night are all too short by one second.
This may not be a problem for handling your calendar appointments, but it can muck up all kinds of scientific applications that require high precision.
I watched the time at Time.gov: 23:59:56 (UTC) =>23:59:57=>23:59:58=>23:59:59=>23:59:60!=>00:00:0 0
It was Amazing! This was the first time for me... *remebers where I was at that moment
"The test of the morality of a society is what it does for it's children." -Dietrich Bonhoeffer
"Happy New Year's" is short for "Happy New Year's Day".
The most rabid believers in American Exceptionalism are the exact same people whose policies are destroying it.
Original poster is slightly wrong - it's not the length of the 1900 ephemeris second,
it's the fact that the Earth, like all of us, is getting older and slowing down, so that
the 2005 "Earth rotation" second (i.e. 1/86400 of one spin of the Earth) is longer than
the 1900 equivalent and longer than the atomic time (SI) second. Instead of changing
the length of the second, it is currently deemed less painful to keep using the old
length and stick in an extra second every now and again.
Since this depends on the slop of the Earth's interior, it's not a fully regular and predictable thing - we might even have to remove a second one year.
REALTOR® is actually a registered trademark, which seems much like "realator" as you say. Although it does sound like it could be an "official" contraction, it's made up.
If you care to know, someone decided, it would seem, to make up a word in order to create "de facto regulation" of an industry--that is, anyone can call themselves real estate agents, but only those who get trademark license (possibly by passing a test on how well they understand real estate agency or REALTY) can legally call themselves REALTORs. And people are "supposed" to prefer a REALTOR over a real estate agent (at least that's the hope of the company owning the name REALTOR--I don't know whether it works or not).
On BBC 1, the clock was counting down and went 5-4-3-2-1-1-0. The people in the streets were just waiting for the bell of Big Ben to strike midnight -- there's no second hand.
hopefully you don't mean that literally, or it's a bug (although an admittedly minor one); the change didn't happen at midnight for most of the world. for example, it was 19:00:60 in EST.
i speak for myself and those who like what i say.
That may have been caused by different lenghts of time delay. not all networks use the same amount of time delay on their live feeds.
It's inserted at UTC 23:59:59, which would be 6:59:59 PM in New York.
Some networks use a time delay to filter out profanities. Also it might be because the feed you're watching goes thru a sat link before reaching your affiliate.
The relationship between GPS and UTC is broadcast from the constellation in the navigation data stream that also transmits time stamps, satellite ephemerises, a variety of correction parameters and other stuff I don't understand/remember :)
GPS time just counts intervals, and it started the count in weeks, days, seconds in January, 1980. The system is aware if UTC though, and one of the various messages sent from the satellites includes the UTC offset. So if you receive and decode that message you'd know the UTC time.
As of yesterday, the difference between UTC and GPS time is 14 seconds.
http://maia.usno.navy.mil/ser7/series14.txt
Last year during the Superbowl it was noticeable at my house, I had 3 TVs tuned to the game, 2 via DirecTV and another using rabbit ears, the over the air broadcast was easily 2-3 seconds ahead of the DTV broadcast. This is one of the reasons that the Sport Betting Houses that allow betting up until play completion don't allow cellphones, because you could have someone watching via a faster source or at the game itself, feeding you what's going to happen.
We (A national UK broadcaster) had a countdown clock (2 identical computers). It was linked from the corp's central ntp server (in turn via GPS), but generally it's a PC clock. Normal broadcast equipment runs off a time code generator that's slaved to GPS.
It wasn't far off the pips on radio 4 analog (ignore big ben etc) in the gallery.
After leaving the gallery, it travels down to one CTA, then another, then another, then gets split, and is sent via seperate routes to the main transmitter in Crystal Palace. Other regions outside London recieve their feeds via various routes.
DTT is sent seperatly, and the signal is encoded (with major delay) as a low bitrate (to the local transmitter), and a high bitrate (to nations/regions) which can be opted out of (I'm a little hazy on this bit).
Additonally DSat is encoded then uplinked to a satelite.
As a consumer, if you recieve digital there will be an additional delay in decoding.
The point is that the time might be fine in the studio, however it goes through a lot of equipment that adds a lot of delay, and different networks will have different delays, different equipment etc.
Now how do you line your studio up? Based on the studio output, the analog reception from a nearby transmitter, the analog reception from a 2nd or 3rd level slave, the digital reception from one of many different transmitters (each with different equipment encoding with a different delay), from satelite (with the 3/4 second bounce plus digital encoding), and how do you account for various decoders?
That's the problem for a normal new year broadcast. Add in a leap second (99% of equipment out there will not accept 23:59:60 as a valid time) and you've got even more problems.
In the UK the most accurate broadcast signal you'll get is the pips on Radio 4 LW.
If you want to know the real time, get a GPS system.
(By "solar" I don't just mean sundials. I mean clocks that are set by pointing the hour hand straight up at noon, which is how all clocks were set before time zones were invented.)
I think what you were trying to say is, "most NTP servers are corrected against official UTC time signals."
The big argument about leap seconds is that the computer folks want to eliminate them, but the astronomers are upset because the useful bit of information that tells how many seconds TAI is off from UTC is transmitted in a field that can only hold a number up to +/- one second in some time transmission protocols. So after a missed leap second, asatronomical time wil lbe off from UTC by an unspecified amount, which could be bad for anyone who uses UTC time to do astronomy. (Since UTC is the time that's transmitted around the world, this is important.)
The determined Real Programmer can write Fortran programs in any language.
No. There is only one leap second and it was added simultaneously worldwide at 23:59:60 UTC. This means the leap second was at 18:59:60 EST or 15:59:60 PST.
The only people who sould have the leap second at 23:59:60 local time and thus extend the final 10 seconds of their new year's countdown would be places where local time is GMT.