Re: What problems do leap seconds *really* create?

2003-01-30 Thread Steve Allen
On Thu 2003-01-30T00:28:57 -0800, Ken Pizzini hath writ: Right, but in its way UT1 is king because that is the measure of earth-position time which is used in the definition of our current time standard, UTC. I would go so far as to argue that UT1 is not time, but angle. UT1 does not measure

Re: What problems do leap seconds *really* create?

2003-01-30 Thread Markus Kuhn
John Cowan wrote on 2003-01-30 13:01 UTC: Markus Kuhn scripsit: Unix timestamps have always been meant to be an encoding of a best-effort approximation of UTC. Unix is in fact older than UTC. This is getting slightly off-topic, but Unix slowly evolved and was reimplemented various times

Re: What problems do leap seconds *really* create?

2003-01-30 Thread Clive D.W. Feather
John Cowan said: Fact 2 is that the old 1980s pre-POSIX Unix manuals talked about GMT and not UTC. This strongly suggests that the authors were unfamiliar with both TAI and UTC. The seconds they refer to behave more like UT1 seconds than like TAI/SI seconds, i.e. they are Earth rotation angles

Re: What problems do leap seconds *really* create?

2003-01-29 Thread Markus Kuhn
John Cowan wrote on 2003-01-29 17:56 UTC: The problem is that they are not announced much in advance, and one needs to keep a list of them back to 1972 which grows quadratically in size. Is this a real problem? Who really needs to maintain a full list of leap seconds and for what application

Re: What problems do leap seconds *really* create?

2003-01-29 Thread John Cowan
William Thompson scripsit: Any application which seeks to calculate the difference in time between two events recorded in UTC time needs to know if there are any leap seconds between the start and stop time. For example, suppose you were studying solar flares, and analyzing some data taken

Re: What problems do leap seconds *really* create?

2003-01-29 Thread Rob Seaman
Those of us with a day job may be having a hard time keeping up with the messages as they arrive fast and furious :-) # The need for leap seconds is not caused by the secular slowdown # of Earth's rotation (which is less than 2 milliseconds per century) # but by irregular variations in this

Re: What problems do leap seconds *really* create?

2003-01-29 Thread Steve Allen
On Wed 2003-01-29T15:43:24 -0700, Rob Seaman hath writ: Please! Let's talk about ways to improve UTC and civil timekeeping. And let's take the appropriate amount of time to reach a decision - say - 40 or 50 years. In the mean time, let's pay attention to the real question, which is how to

Re: What problems do leap seconds *really* create?

2003-01-29 Thread Mark Calabretta
On Wed 2003/01/29 15:43:24 PDT, Rob Seaman wrote in a message to: [EMAIL PROTECTED] Basically we don't have leap seconds because the Earth's rotation is slowing down (by transfering angular momentum to the Moon). Rather, we have leap seconds because the Earth has *already* slowed down since