[time-nuts] Leap Quirks

[M. Warner Losh]

In message: <m3hc4gqdjb.fsf at lugabout.jhcloos.org>
            James Cloos <cloos at jhcloos.com> writes:
: >>>>> "Warner" == M Warner Losh <imp at bsdimp.com> writes:
: 
: Warner> So what you've done is created a new time scale that is a UTC
: Warner> from 1972 forward, but a simplified form of UTC prior to 1972
: Warner> that didn't match what UTC was doing then.
: 
: Grrr!  Except s/you/they/; I didn't invent.

Yea, I was speaking a bit rhetorically :-)

: So right isn't quite, err, right.  I wonder whether the Olsen db can
: be fixed to account for that?  right/UTC and posix/UTC currently are
: identical for all (time_t)LONG_MIN <= time_t < 78796800.

Yes.  I'd forgotten that the Olsen db doesn't deal with rubber seconds
at all.  It is a pain in the *** to try to do that, and of dubious
value.  I tried once to create a library that coped with them, but
gave up when I realized it wasn't a useful problem to solve.

: Thanks for the reminder.  I had forgotten that entirely.  (And am 
: only just vaguely remembering that I used to know that fact.  [SIGH])

It is certainly underdocumented...

: Warner> Yet another hazard of high precision time keeping that few
: Warner> people get right
: 
: Part of what makes this list's name so appropriate is just how hard
: it is, all things considered.  That is also what makes it enjoyable.

Yes.  Very enjoyable.  Of course, I could live without all this
complexity, frankly, and be happier.

: Warner> An understandable simplification, to be true, and one that's
: Warner> often made...
: 
: Often, I'm sure, because not all sources document/remember that fact.

Yea.  In another life, I defined a datum as 'number of SI seconds
since 01-01-1972 00:00:00 UTC + 63072000'.  Which is what we're
talking about here, no?  This is number of seconds since 1970, with
the 'oddball' rubber seconds counting as SI seconds.

Warner