In message <[email protected]>, Rob Seaman writes:
>I have (tediously, bombastically, endlessly) asserted that civil time >IS solar time. This is a statement of requirements. Requirements >describe the problem space. And you have repeatedly tried to ignore the question of how large the civil-solar tolerance is, can or should be. I would estimate that the majority of the worlds population are not within one hour of solar time at any point in the year. China, for instance, is one single timezone. But maybe part of that problem is in the moniker "civil time", which we have never fully agreed what means ? How about we operate with _three_ kinds of time and one kind of geophysics: "Timekeeping Time": What timekeeping scientists work with, for keeping time. Mind you: "Time", not 'Earth Orientation". Today this would be TAI, TAL etc. "Earth Orientation": A set of physical parameters describing the motion of this planet, including its rotation. Today this would be UT, UT1, UT2, and half of UTC. "Scientific/Technical Time": What computers and scientific experiments use internally, in order to be able to communicate temporal relationships unambiguously. Today this is UTC + Leap-second table + Leap-second announcement. "Human time": What people see on their clock. Today that is usually UTC, fuzzed by political concepts such as DST. Obviously, Neither ITU nor BIPM has any control over what "Human Time" is or how it works. National and federal lawmakers decide that, often illadvisedly, and occationally very stupidly. China, as I recall, is one single timezone, and some places countries have 30 minute offsets from UTC I belive. If any national government wants to do something stupid to human time in their country, nobody can prevent them from doing so. Timekeeping Time and Earth Orientation should be left to the scientists, and should obviously be established and maintained as precise as funding will allow. UN and ITU has no mandate in this area, so the relevant organizations (IAU etc) are free to do as they please. What is left then, is the Scientific and Technical time. Which is exactly what UTC was intended to be originally, and why the definition and possible redefinition of UTC happens in an obscure technical corner, of a UN organ most people have not heard about. Now, please make your argument, that Scientific and Technical time should be polluted by earth orientation parameters ? Yes, it would be convenient for astronomers pointing their telescopes, but do you have any other argument than that ? 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 [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
