On Wed 2015-03-11T11:04:57 -0700, Tom Van Baak hath writ: > The entire purpose of UTC is to provide a single timescale for all > human-related activity.
And UTC has failed miserably. POSIX says UTC has no leaps. Google says UTC has occasional days with stretches of seconds which are of varying lengths. De facto, there is no single UTC time scale. Unfortunately UTC was originally sold as the ultimate and complete solution to two separate problems: seconds of uniform frequency and mean solar time. As Rocket J. Squirrel said to Bullwinkle Moose "That trick never works." See a web snip from the recent European Postal & Telecom prep meeting CPG15(15)024R1_Minutes_of_CPG15-6.docx http://www.yme.gov.gr/getfile.php?id=5978 6.1.5 WRC-15 Agenda item 1.14 - Leap Second Two opposing proposals for a New ECP on agenda item 1.14 which are found in Annex 16 to CPG15(15)002, one based on Method A and the other on Method C of the draft CPM text, have been introduced and considered. No agreement could be reached and CPG15-6 tasked PTA to continue its work. France questioned whether the matter of the time scale should be considered by the BIPM (International Bureau of Measurements and Weight) instead of the ITU. Some Administrations stated that the consequences of decision on this matter are quite important for radio systems, in addition to the fact the ITU being a treaty based organisation and BIPM is not. The draft CEPT brief on AI 1.14 was approved and can be found in Annex IV-15. CPG noted the draft ECPs. Based on discussions at PTA, CPG considered editorial updates to the draft CPM text and adopted the contribution to CPM15-2 (see section 7). "Statement by the Russian Federation: The Russian Federation does not support CEPT contribution to CPM on agenda item 1.14 as CEPT position on this issue is not defined yet and that part of proposed modifications to the draft CPM Report is premature. Moreover contribution includes reference to the Workshop presentations which was not adopted through ITU-R study process." This snip lacks some of the referenced documents, and the UK is not even mentioned in this summary, but it is clear: No consensus. Elsewhere on the web are snips of other preparatory documents. Almost violent discord. So much so that <tin foil hat on> when Dr. Matsakis opined that he would not want to be flying during a leap second I pondered whether there are some folks so opposed that they are planning to engineer a leap second catastrophe in order to force the vote at WRC-15 in November. <tin foil hat off> But the bottom line for engineers who are implementing operational systems that depend on timing is much simpler. If you want to engage with a 15 year long international flame war where people cannot agree on elapsed time to within several seconds, then go ahead, choose the internationally-recommended UTC. But if you want to get something working that does not get bothered by differences of several nanoseconds, then ignore the international recommendations and choose GPS time, Galileo, BeiDou, the Indian satellite system time, or some PTP-based system via a device which claims to be using one of those to supply TAI. -- Steve Allen <[email protected]> WGS-84 (GPS) UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
