Re: [LEAPSECS] operational time -- What's in a name?
On Mon, 31 Mar 2008, Clive D.W. Feather wrote: Um, what buttons on the back? My kitchen RC clock has none such (probably because just about all of the UK is in the same time zone). Mine has buttons to request a radio sync and for manual setting. http://www.precisionclocks.co.uk/Instructions%20(PDF's)/PREC0002.pdf Tony. -- f.anthony.n.finch [EMAIL PROTECTED] http://dotat.at/ SOUTHEAST ICELAND: NORTHEAST 7 TO SEVERE GALE 9 VEERING EAST 5 TO 7. VERY ROUGH OR HIGH . OCCASIONAL RAIN OR SLEET. MODERATE OR POOR. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Tony Finch writes: It seems that the reason my MSF clock didn't switch to DST was its position - moving it allowed it to resync correctly. This is one of my major issues with radio-sync clocks: they seldom tell you they have no idea what time it really is. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Fri, 28 Mar 2008, Steve Allen wrote: Part of the beauty of distinguishing broadcast time signals from UTC, while continuing both, is that it allows separate issues to be addressed separately. I allow that the broadcast time signals should be leap free, for there are many operational systems which will benefit from that simplicity. From many quarters it seems that is a really big issue. If we change the name of the broadcast signals then they can go leap free on a very short time scale. Right after the next leap second would likely be a really good time. So you think that the millions of existing radio controlled clocks and watches should stop showing civil time? Tony (wondering why his MSF clock failed to switch to BST). -- f.anthony.n.finch [EMAIL PROTECTED] http://dotat.at/ IRISH SEA: VARIABLE 4 BECOMING SOUTH OR SOUTHWEST 5 TO 7, PERHAPS GALE 8 LATER. MODERATE OR ROUGH. SHOWERS THEN RAIN. MODERATE, OCCASIONALLY POOR. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
Tony Finch said: So you think that the millions of existing radio controlled clocks and watches should stop showing civil time? They already do. Tony (wondering why his MSF clock failed to switch to BST). Mine changed fine, though it was a bit moot since the entire family was in Italy until about 6 hours before. But MSF reports UTC, not civil time (GMT). -- Clive D.W. Feather | Work: [EMAIL PROTECTED] | Tel:+44 20 8495 6138 Internet Expert | Home: [EMAIL PROTECTED] | Fax:+44 870 051 9937 Demon Internet | WWW: http://www.davros.org | Mobile: +44 7973 377646 THUS plc|| ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mon 2008-03-31T12:20:06 +0100, Tony Finch hath writ: So you think that the millions of existing radio controlled clocks and watches should stop showing civil time? Yes, that is, yes to a subsecond precision. They would be showing TI instead of UT, another international standard, and a difference which (to replay the words of the folks who would abolish leap seconds) would amount to less than two minutes by the end of the century. I expect that Casio, Timex, and the other radio-controlled walk clock and wristwatch manufacturers would cry all the way to the bank as people bought new ones when the difference in seconds became notable to those who care that much. And for the rest, most of those timepieces would have disintegrated from their poor construction prior to the time when the difference between TI and UTC was larger than a non-radio-controlled timepiece. -- Steve Allen [EMAIL PROTECTED]WGS-84 (GPS) UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99855 University of CaliforniaVoice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
Rob Seaman said: Ease of setting is a great feature. But setting a clock also involves checking that you set it correctly (selected the right combination of buttons on the back). Um, what buttons on the back? My kitchen RC clock has none such (probably because just about all of the UK is in the same time zone). -- Clive D.W. Feather | Work: [EMAIL PROTECTED] | Tel:+44 20 8495 6138 Internet Expert | Home: [EMAIL PROTECTED] | Fax:+44 870 051 9937 Demon Internet | WWW: http://www.davros.org | Mobile: +44 7973 377646 THUS plc|| ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
although naive math is, well, naive, more code exists that assumes, for example, that midnight it time_t % 86400 == 0 than you want to believe. Changing this is really bad karma. The current situation is that code like your example does not accurately reflect reality. I advocate changing the code. You advocate changing reality. Fuck the telescopes software. it is order of magnitudes less common than anything else as to be irrelevant than things like ntp. Attitudes like fuck certain people's software don't seem useful to me. Leap seconds are evil and must die. That is an opinion that not everyone shares. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Fri 2008-03-28T15:28:53 +, Tony Finch hath writ: The POSIX standard guarantees that what Warner wrote is correct. The POSIX standard is in denial about leap seconds with respect to UTC. I don't know about international standards, but in people I'm sure that's not a good sign, and I try to avoid such. -- Steve Allen [EMAIL PROTECTED]WGS-84 (GPS) UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99855 University of CaliforniaVoice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Fri 2008-03-28T16:04:49 +, Poul-Henning Kamp hath writ: My personal preference would be to bite the bullet and live with the 128bit memory hit: utc_t 64i.64f (big enough, small enough) Whereas I am not against the notion of such, I find that nomenclature to be problematic, for UTC did not exist prior to 1960. We must not forget the examples of Sweden http://en.wikipedia.org/wiki/February_30 and that, contrary to what everyone thought at the time, Julius was assasinated on March 14, not 15 http://en.wikipedia.org/wiki/Roman_calendar#Converting_pre-Julian_dates It is never possible to get people to fix their notion of what time they thought it was. Any epoch-based proleptic time scale using uniform counting is a conventional artifice which is unlikely to correspond to any other retrospective scheme in current use or any scheme which was contemporary at the given epoch. Even if it is a broadly published international standard, nothing constrains posterity from misusing the definition, or even changing its notion of the meaning of a time scale and creating more such examples. It seems unlikely to me that any organization has the standing to assert an unambiguous time scale that is both operational and comprehensive across history. If anyone gets close, I am sure that there are obsessive/compulsive programmers who will write conversion libraries in all the currently popular computer languages, and I am also sure that those libraries will be ignored by a lot of systems which do not care to be comprehensive. -- Steve Allen [EMAIL PROTECTED]WGS-84 (GPS) UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99855 University of CaliforniaVoice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
Steve Allen scripsit: The POSIX standard is in denial about leap seconds with respect to UTC. I don't know about international standards, but in people I'm sure that's not a good sign, and I try to avoid such. Not exactly. What it denies is that there is necessarily 1s between values of time_t that differ by 1. Sometimes there is 2s. -- Well, I'm back. --SamJohn Cowan [EMAIL PROTECTED] ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Steve Allen writes: On Fri 2008-03-28T16:04:49 +, Poul-Henning Kamp hath writ: My personal preference would be to bite the bullet and live with the 128bit memory hit: utc_t 64i.64f (big enough, small enough) Whereas I am not against the notion of such, I find that nomenclature to be problematic, for UTC did not exist prior to 1960. Agreed, but at least that is only a matter of educating historians and not politicians and pedestrians. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
although naive math is, well, naive, more code exists that assumes, for example, that midnight it time_t % 86400 == 0 than you want to believe. Changing this is really bad karma. The current situation is that code like your example does not accurately reflect reality. The POSIX standard guarantees that what Warner wrote is correct. I'm not arguing if Warner is correct or not if he claims that POSIX claims that time_t % 86400 == 0 means midnight. I'm also not arguing that he is correct that lots of code assumes this. My claim is that if POSIX defines time_t % 86400 == 0 as being midnight than POSIX doesn't reflect reality, since people think midnight as being UTC rather than POSIX. POSIX may define 2+2=5, but if it did it wouldn't be correct. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Greg Hennessy writes: My claim is that if POSIX defines time_t % 86400 == 0 as being midnight than POSIX doesn't reflect reality, [...] Well, POSIX clearly doesn't match the scientific definition of UTC, but as which of the two is more real is mostly a matter of philosophy I think. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
Greg Hennessy scripsit: My claim is that if POSIX defines time_t % 86400 == 0 as being midnight than POSIX doesn't reflect reality, since people think midnight as being UTC rather than POSIX. When it's midnight UTC, a properly time-aware Posix system *will* report that time_t % 86400 == 0. That's about as congruent to reality is any system can get. Unfortunately, it reports the same thing at 23:59:60 UTC on days when such a second exists. -- A rose by any other nameJohn Cowan may smell as sweet, http://www.ccil.org/~cowan but if you called it an onion [EMAIL PROTECTED] you'd get cooks very confused. --RMS ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
Working backwards through the messages. On Mar 28, 2008, at 1:22 PM, M. Warner Losh wrote: How is that any different than the ITU defining UTC to generally behave as time has behaved for centuries, except that leap seconds have a new notation (the :60 stuff)? ITU didn't create UTC since they didn't exist at the time. Grep for messages from Mark Calabretta as to why UTC isn't multi-valued. Rob Seaman NOAO ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 11:44 AM, Poul-Henning Kamp wrote: Well, POSIX clearly doesn't match the scientific definition of UTC, but as which of the two is more real is mostly a matter of philosophy I think. Both are human constructs. It is mean solar time that is real, that is, the sidereal day augmented by 3m56s to account for annually lapping the sun. Rob Seaman NOAO ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 10:08 AM, Steve Allen wrote: It seems unlikely to me that any organization has the standing to assert an unambiguous time scale that is both operational and comprehensive across history. Indeed. This is a function of Mother Earth. Smash a clock offering a representation of mean solar time. The repaired clock could be reset via observation from first principles. Smash an atomic clock. Then what? Rob Seaman NOAO ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 9:12 AM, Poul-Henning Kamp wrote: But our problems with POSIX may pale soon, when the politically ram-rodded, 7000 pages long OOXML standard for office and business documents gets ratified by ISO as a rubberstamp standard. As far as I know that standard gets none of leap years, timezones much less leap seconds right. And we're to trust the international standards process to define the fundamental architecture of timekeeping? ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 9:04 AM, Poul-Henning Kamp wrote: Even if we decided to fix time_t's little red wagon for good, and got the economic resources to do so, we would be very hard pressed to find the competent man-power to carry it out reliably. I'm fascinated by your choice of this line of argument. People are incompetent - let's give up. Why then should we care about any of the trappings of modern civilization? However complex the current worldwide system of systems comprising our civilization, it will only get more complex. Whenever we choose to address some technological issue, it will be better to use system engineering best practices to attempt to constrain that complexity. If you compare with the other crap we put up with from computers, and the sheer mindbogglingness of the workarounds people put up with, I am sure that the disappearance of leap seconds would not even register on the publics radar. System engineering is as much or more about characterizing the problem as about offering a solution. Your personal surety is of little benefit to this process. Risks that aren't characterized in advance are likely to register on the public radar (perhaps literally) in retrospect. My personal preference, would be that we create a new definition of time representation for computers, preferably in a binary format so the math gets faster and less buggy. This is a nice discussion of options (absolutely no irony here). My central point all these long years is that we have yet to even scratch the surface of capturing coherent requirements for civil timekeeping in the modern world. Before we design a solution (or scrap the interim solution that we already have), wouldn't it make sense to figure out the full nature of the problem it is meant to solve? Provided we get 10 years notice of leapseconds, that timescale can contain leap seconds. If we don't get at least 10 years notice, it should not suffer from them. We would all be happy with all the notice we could get. This is an orthogonal concept to the best scheduling cadence for clock updates of whatever sort. It doesn't take much insight into human nature to think that a monthly cadence will get more productive attention than a decadal or millennial cadence. Rob Seaman NOAO ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 9:04 AM, Steve Allen wrote: But if we call POSIX time_t by a new name (say TI) which has international status and properties which match the specified characteristics of time_t then what we have is enlightenment. How about calling it GPS? The assertion is that TAI itself is unacceptable as a practical time scale. The notion is that we'll turn UTC into that time scale. However, by doing so, UTC will no longer be a flavor of Universal Time. The largely unstated assumption is that folks needing actual Universal Time will use UT1 instead. Note, however, that UT1 is unacceptable as a practical time scale since like TAI it is retroactively computed. Rather, how about implementing Steve's scheme, but using GPS and UTC? Both would remain practical and transportable time scales. Both are known to the public already. GPS is clearly the most flagrantly successful timekeeping standard by any marketing standpoint. And after all, this is really just the moveable timezone notion of civil timekeeping, but turned into a functional system concept for evaluation purposes. Simply saying we'll make up the difference by smooshing the timezones around as needed is not equivalent to a coherent plan. That said, any such system needs to pass through a system engineering planning process before it can be deemed to be a solution to any problem. (Because otherwise there will be no clearly described problem to be solved.) Rob Seaman NOAO ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 4:42 AM, Poul-Henning Kamp wrote: This is exactly the flagday that will make the upgrades to a few hundered telescopes look like peanuts. In grad school one of my housemates was a Swedish postdoc with an inordinate fondness for Jack Lord and Hawaii Five-O (http://www.youtube.com/watch?v=rNk_wlqFG5o ) Per had an entertaining description of the flagday when Sweden switched to right-side driving in 1967. Don't sell the entertainment value short as a way to bring timekeeping to the attention of a vast new public. If it's peanuts to you, perhaps you'll help with our funding for this upgrade? What new features should we expect in this release? :-) ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Rob Seaman writes: However complex the current worldwide system of systems comprising our civilization, it will only get more complex. There are actually a significant undercurrent that indicates that this will not be the case. Most recent technology, while rich in features, gets used to nowhere near it's technological potential, because people simply cannot figure it all out. The thing that seems to be widely overlooked by technologists, possibly by the high-IQ crowd in general, is that Moores law does not apply to wetware, and consequently, there very much is a fixed upper limit for how much technology you can push on the general population. We can do the stiff upper-lip and thumb our noses at this well documented phenomena, or we can accept it and realize that successful technology in the future is that which makes things simpler instead of more complex for people. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Rob Seaman writes: On Mar 28, 2008, at 9:04 AM, Steve Allen wrote: But if we call POSIX time_t by a new name (say TI) which has international status and properties which match the specified characteristics of time_t then what we have is enlightenment. How about calling it GPS? Only if you can convince ISO9000 consultants that there is a traceability from this timescale (as distributed by NTP ?) to UTC which forms the basis of legal timekeeping. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
In message [EMAIL PROTECTED], Rob Seaman writes: Per had an entertaining description of the flagday when Sweden switched to right-side driving in 1967. You know the danish version of that story ? They were afraid that it would be total mayhem to do it in one go, so the phased it in: First the lorrys and trucks, then some days later the smaller cars :-) Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 4:12 PM, Poul-Henning Kamp wrote: The thing that seems to be widely overlooked by technologists, possibly by the high-IQ crowd in general, is that Moores law does not apply to wetware, and consequently, there very much is a fixed upper limit for how much technology you can push on the general population. Excellent points - I'll buy the first round if we're ever at the same conference. Most Mac users would take credit for saying it first :-) High-IQ is an adjective devoid of semantic content, however. See SJ Gould's Mismeasure of Man or Gardner's Multiple Intelligences. Binet invented IQ to discover the underperforming tail of the curve, not smart people. We can do the stiff upper-lip and thumb our noses at this well documented phenomena, or we can accept it and realize that successful technology in the future is that which makes things simpler instead of more complex for people. 100% agree, but the definition of simpler is maps elegantly onto the real world. The Earth does rotate, the Moon does steal its angular momentum, the Sun does illuminate our lives. ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] operational time -- What's in a name?
On Mar 28, 2008, at 4:14 PM, Poul-Henning Kamp wrote: Only if you can convince ISO9000 consultants that there is a traceability from this timescale (as distributed by NTP ?) to UTC which forms the basis of legal timekeeping. Ahoy! A requirement has been discovered! ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
