[ntpwg] Further to the timestamping issue

[M. Warner Losh]

In message: <5CD5936A-CDD2-4A17-ACFE-8149C2DC0BE8 at noao.edu>
            Rob Seaman <seaman at noao.edu> writes:
: On Jun 19, 2008, at 8:04 AM, TSG wrote:
: 
: >> My fundamental point is that UTC permits much more flexible leap
: >> second scheduling than has been demonstrated to date.  NTP might have
: >> to adapt to this in the future.
: >
: > Not if its used in proper auditing of IT operations. Leap Seconds  
: > are a nightmare for logging systems because they require special  
: > handling and integration across an entire entitie's operations.
: 
: I don't discount auditing requirements, although it isn't clear that  
: NTP's requirements are the same as your company's.  That the Earth  
: orbits the Sun and has a large nearby Moon are a bit more fundamental  
: than either.  We can disagree about the implications of all sorts of  
: requirements.  Basing a discussion on requirements is generally more  
: productive, however, than jumping directly into each other's nightmares.

That only matters if you think that having civil time that's closely
tied to the mean solar time is important.  After all, there's very few
people that live at the meridian where the localtime is defined.
Today, my clock is just about an hour off from mean solar time due to
daylight savings time.  It just doesn't matter enough in people's
lives, and causes other problems, such as the logging issues above.

I know Rod loves leap seconds.  I doubt that will ever change.  But
they are a big pain in the ass that nobody ever bothers to get right
(due to the cost, ignorance if the issues, etc), but everybody wants
to be right.  It would be easier to publish DUT1 go on the drift and
move national time zones every hundred years or so.  Lord knows the
politicians move them around a lot more often than that.

Rod is pedantically correct too when he says that UTC can do leap
seconds more often than twice a year.  The large number of things that
break if that were to happen shows just how fragile the leap second
scheme is.  ntpd is but one example (since it had a filter to only
announce leap seconds at the end of June and December), and ntpd is
written by people very clueful about leap seconds.

Anyway, enough ranting.  Leap seconds are evil and must die.  Others
will no doubt disagree.

Warner