2016 will be one second longer
sciencebulletin.org
sciencebulletin.org
If ignored since their introduction in 1972, official time would be out of sync with the Earth's rotation by 26 seconds. There's been a lot of running around and gnashing of teeth to correct 1.845668179868485e-7 error that isn't even an error most of the time. The 26 seconds of error fleshes out as 7.389 meters at the equator when using celestial navigation and for anything that accurate we use radio signals not a sextant.
The Earth's rotation and revolution are useful abstractions at a certain level of granularity. But the reason we have atomic clocks is because those abstractions break down when we need precise measurements of reality. Reality is real because the rotation and revolution of the Earth are not cosmological constants. Leap seconds are an expression of the superstition that humans control the arrow of time: as if one thing happening after another would cease to be the case without them.
"Adding leap seconds is a waste of time" I see what you did there. And agree!
A few minutes ago, when the screenshot was taken, this was second #501074 in week #1928.
As a courtesy to users, GPS transmits the current number of leap-seconds inserted in UTC (currently: 17) and the fact that a leap-second will be inserted the next occasion (end of this year: "LEAP PENDING!"). That's of course very helpful when you are using GPS disciplined clocks for timekeeping.
Unless you are doing something very interesting, that relies on some absolute standardized time (ie. not relative measurements) and requires great precision, you'll throw away clocks faster than they will accumulate errors. That's a feature, not a bug.
The earth rotates about 12 km along the equator in 26 s.
Is the error of ~7 m for determining your position north-south wise? East-west it should be about 12 km then I think.
Not sure how I missed that in previous discussions of leap seconds, but now I can comfortably spend my leap second in 2016 basking in this knowledge.
Just like timezones and calendar changes, leap seconds are a display issue. While obviously very important in some circumstances there's no need to keep track of them through absolutely all of our code.
If the way you measure time takes leap seconds into account, you have no way of saying "exactly X Système international seconds from now". This is a big deal.
Note that this is the case for anyone using POSIX time, which inherently assumes that hours start on multiples of 3600, and has to be adjusted or smeared when a leap second happens.
But I've never seen a system that follows your recommendation, using TAI as the internal time and something like TAI-5:00:36 as the local time, except for GPS devices.
Yes. And it's not just real-time; even when just displaying dates and times, an off-by-one error at any granularity can bump it into the next year.
I guess what I'm wondering is how does the decision to add a leap second here or there find its way into system clocks, such that it knows whether:
new Date(1483228800000).getUTCFullYear()
Depends on where one is. It takes 24 hours for the New Year to propagate. The maximum error during propagation is < 0.00115741%
Assuming that .getUTCFullYear() is accurate, the maximum error for a leap second is:
1 / (365 * 24 * 3600)
= 3.1709791983764586e-8
The advantage of this is that 1483228800000 is definitely the start of 2017 (and in general, UTC days start on multiples of 86400 seconds, or 86400000 in JS). The disadvantage is that Date(1483228799999) could happen twice, and the first time it would be followed by Date(1483228799000).
In your application, you have to be able to cope with time going backwards for a moment. (But this is already true whenever your system contacts an NTP server.)
Counting the leap second twice is more of a quick hack used in computers, but it's not how it actually works
Everybody brace yourselves for that second, lest another cool person die! :P
With more TV channels, radio stations, and the internet, the number of public figures we're exposed to on a regular basis is far greater than any generation before us. And like all of us those people die, and will keep dying, and the half-hearted and self-centered social media mourning will become even more commonplace.
I, for one, can accept celebrity deaths, but I'm not sure if I can accept the annoying cultural impact they seem to be having.
Even before we approach Bowie it's been pretty dreadful.
https://www.youtube.com/watch?v=eFTLKWw542g
Although it covers 40 years:
This is the first time I've heard it mentioned. For finding it insufferable, you just spread the word.
Don't get me started on 1942.
A good resource for red hat linux is https://access.redhat.com/articles/15145. And another resource is https://ics-cert.us-cert.gov/sites/default/files/documents/B...
In real terms, does it really count?
A few months back, a friend of mine was so happy when she got on a scale and found that she's lost one pound. One pound!
GPS needs something more precise anyway, it's not for these systems that we need to include whole-second corrections. And besides, GPS doesn't actually use leap seconds.
10,9,8,7,6,5,4,3,2,1,[Insert Shell Code]
/root/ #:
(Sorry, drunk)