On Thu 2005-08-04T15:44:17 +0100, Ed Davies hath writ: > Perhaps it would be a mistake for the relationship between > civil and SI seconds to be anything other than identity.
I would agree for planning purposes for the next century. > On the other hand, the schedule for > the day would be in civil seconds. Of course, the schedule > doesn't need to be held to the exact second (though it's > often done pretty close to that) but somewhere in the chain > there would have to be a switch over. Where, exactly? I don't know what things are like in the UK, but US viewers are all too familiar with the fact that civil time does not correlate with TV program start and stop time to within a minute. Thursday night viewers are well aware that CBS always runs CSI right up to, or sometimes past 22:00 while NBC starts ER as much as two minutes before 22:00. Undoubtedly there are other examples, but I have other things to do. The networks apparently believe that strategies aimed at shaming the viewers for non-loyalty are more important than precise time. I suppose that the A.C. Nielson company has already had to adjust its ratings gathering processes in order to accommodate such things. > Clearly, there's a use for a > "solar second" but perhaps it's even more specialised than > a sidereal second. This is not directly on the topic of discontinuing leap seconds, but the sidereal second became undefined as of 2003-01-01 when the Vernal Equinox was abandoned in favor of the NRO/CEO/CIO. Of course at the same instant the mean solar second of UT1 also lost all connection with its original intent. For most practical purposes the old FK5-based definitions will remain adequate throughout the next century, or two, but after that... -- Steve Allen <[EMAIL PROTECTED]> WGS-84 (GPS) UCO/Lick Observatory Natural Sciences II, Room 165 Lat +36.99858 University of California Voice: +1 831 459 3046 Lng -122.06014 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m