Having read the article, I for one am glad they're not leaping to any conclusions without a second thought.
Should the leap second be eliminated?
21–25 of 25 posts
Re: Should the leap second be eliminated?
#22This article doesn't give clear enough reasons for abolishing leap seconds. One passage says: > But those seeking to abolish the leap second say these one-second jumps are becoming increasingly problematic for navigation and telecommunication systems that require a continuous time reference. These include satellite navigation, financial services, the internet, flight control and power systems, among others. But elsew…
Well, let me phrase it a little more analytically, then. The biggest reason to switch UTC to atomic time is hacker-cultural. Basically, many countries have said, in law, "we use UTC." This causes most specifications -- in particular NTP, Javascript, and POSIX timestamps -- to also say "we use UTC -- but we ignore leap seconds." Unfortunately, these specifications are thereby rendered useless and incompatible in a bunch of different ways. NTP servers, we'd like, should just broadcast atomic time, TAI. Similarly, Javascript's Date.getTime() should give TAI, and POSIX should give TAI. But TAI isn't what countries have legally specified -- UTC (and in some cases GMT) is what countries have legally specified.
Governments use UTC because we like the idea that the sun rises at around 6 AM. (Or, on my base-10 clock, at around 0 ki.) But that's when the sun rises -- that's a question of setting a time zone!
So the best way to include leap seconds for now is via time zone information: allow the time zones to drift with leap seconds. Time zones are already pretty crazy and hard-to-anticipate and may change by a much larger offset at even shorter notice (e.g. "This summer, we are not observing Daylight Savings time"). If you can't anticipate upcoming political "leap-hours", your software already can't handle the less-political question of "when is the next leap-second?"
During my free time I've been playing with designing a base-10 clock. (Obligatory plug: http://drostie.org/time/ .) So I've been thinking about this topic off-and-on for a couple years now. During that time I guess I've convinced myself that the right way to handle this is to define a named time zone which implements leap seconds -- this requires derivative time zones. So for example, my clock above automatically assigns to New York the base-10 time zone of "+300". With named time zones, it could shift to leap seconds by passing a law saying "the base-10 time zone in our jurisdiction is instead leap+300." Or perhaps the US as a whole would design their own time zone to standardize a base-10 daylight savings time, and call it "us" and then New York might be in the time zone "us+300".
The goal is to really make specifications designers think, "oh, leap seconds are a cosmetic choice, I'd better just use the base-10 'rational timestamp' format rather than rolling my own implementation of POSIX timestamps." Right now they think "oh GMT is old and UTC is new and everyone knows what UTC is so we don't have to worry about it, right?" -- and they don't get it right.
So is this a technical issue or a diplomatic one? Well, it's technical because it affects technical specifications, but it's nontechnical because there is no good technical argument for using UTC versus TAI -- that's a time zone question, a political or diplomatic question about when you want the Sun to rise.
The only technical situation that I know of is the claim that some old telescopes might be using time to find stars -- and might misalign if the time comes unsynchronized from Earth's rotation. I don't consider this a serious technical difficulty, because those telescopes are manned by hackers smart enough to get a feed of Terrestrial Time and pipe it into whatever clock input was receiving UTC. "Hey look, it uses this NTP server, let's just redirect that DNS query to a smallish Linux box which serves TT over NTP." I think we're smart enough to ignore this technical case.
Re: Should the leap second be eliminated?
#23I know not all of the world observes daylight savings time, but why not coincide any leap seconds/minutes/hours with the changing of daylight savings time? It would at least make it simpler for those who do practice DST.
Re: Should the leap second be eliminated?
#24I like the leap-hour once every 500 years or so idea. But I suspect in practice, it would never be actually assessed. When it comes due, everyone alive would be more accustomed to the 'hour off' times than the 500-years-ago time, so natural tendencies to eschew change in such matters would make following-through on the promised leap-hour unlikely.
We’re willing to shift our clocks by an hour twice a year to “save daylight,” whatever that means. Correcting for 500 years of clock drift is a far more tangible reason. It’s rather pessimistic to assume that the people of 500 years from now would be unwilling to implement this.
I'll be spinning in my grave, cryogenic storage tank, or positronic simulation matrix if our ancestors 500 years' hence are still observing (and thus familiar with) "Daylight Savings Time".
Re: Should the leap second be eliminated?
#25The answer (for software engineering) is to stop thinking of time as a continuous flow with periodic markers such as second, minute, etc. Instead, think of it as chunks.
Mostly one chunk flows seamlessly into another. Occasionally, a chunk is "missing", such as skipping an hour at Daylight Saving. We are already set up to handle that. It would be very simple to add another rule to the DS database to globally add a second now and then.
I really don't see what the problem is.