http://www.youtube.com/watch?v=-5wpm-gesOY is required viewing.
Warner On Jan 7, 2014, at 4:22 PM, Brooks Harris wrote: > Hi, > > First, this is my first posting to your list, forgive me if the subject has > been covered. > > Second, I am a colleague Stephen Scott, also a new subscriber who posted a > question earlier this week - (Subject: Local insertion of leap seconds). > > My question is about the current state of standards concerning time zones. > > Steve Allen's "Time Scales" > http://www.ucolick.org/~sla/leapsecs/timescales.html > <http://www.ucolick.org/%7Esla/leapsecs/timescales.html> is a tremendous help > in many regards, and my thanks and appreciation for the work collected there. > But it seems to side-step explanation of time zones, and its here I'm asking > for guidance. > > I fully understand time zone specifications are fractured. My objective is to > determine what standards are most relevant currently, that is, what standards > may be considered "in force". And where none exist, to state some sort of > rules of "common use" or "common practice" without referring to the > impossibly large collection of local jurisdictions and laws. > > In particular - > > A) "International Date Line", which is probably not standardized except by > local decree, but the "180 degrees from the Greenwich meridian" has > provenance back to the "International Meridian Conference of 1884" (not its > proper name). Is there more modern standard that codifies this in any way? > > B) The "International Meridian Conference of 1884" contains significant > discussion of the idea "That these standard meridians should continue to be > designated as even multiples of fifteen degrees from Greenwich", but there > appears to be no explicit resolution of vote on the topic. I am unable to > pick up the trail from there. There are many references in other conferences > preceding and after the 1984 conference, but I have not discovered any > official action on the subject. Again, is there any modern standard regarding > that issue? > > ISO 8601 describes using "offset from UTC" to indicate "time zone", but as > far as I can tell it does not state either what a "time zone" may be or why > an offset to a "time zone" from UTC might be useful. Is there any other > standard that might describe this relation of UTC (zulu) to the "time zone" > or "local time" more rigorously? > > Of course the definition of "Greenwich meridian" has undergone many > refinements and name changes since 1884. Claude Boucher describes the state > of Formal international recognition of the International Terrestrial > Reference System (ITRS) > > https://www.google.com/#q=Formal+international+recognition+of+the+International+Terrestrial+Reference+System+(ITRS). > > > Are there descriptions of "time zones" amongst the standards in this field? > > And, of course, there is the subject of "Daylight Savings", apparently begun > by George Vernon Hudson. Are there any modern standards or implementation > guidance documents in force? > > I'm aware of tz databse, of course, but here too there seems to be lack of > clarity about what rules are being implemented, or, at least, I've found no > consolidated statements of those rules there. > > Comments and guidence welcomed, thanks very much, > > -Brooks Harris > > > > _______________________________________________ > LEAPSECS mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/leapsecs _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
