Re: [LEAPSECS] A lurker surfaces

From: M. Warner Losh <imp_at_BSDIMP.COM>
Date: Sun, 31 Dec 2006 12:13:42 -0700 (MST)

In message: <20061231184717.GE30208_at_ccil.org>
            John Cowan <cowan_at_ccil.org> writes:
: Tony Finch scripsit:
: > On Sun, 31 Dec 2006, John Cowan wrote:
: > >
: > > However, it's clear that UTC does not contain the sort of jumps
: > > that LCT does, where a single broken-down time may represent
: > > two different UTC seconds.
: >
: > Not if you include the timezone offset in the representation.
:
: Quite so. Or alternatively a standard/daylight flag. The point is,
: people usually don't.

This is the leapsecond problem in a nutshell: While it is possible to
keep enough information around in the representation of time, most
people opt not to do so. It complicates the representation of time,
and is one (or more) pieces of information that need to be carried
around, mostly just to handle weird edge cases. Sure, you can do it,
and some people try. However, there's no standardized way to do so,
and people re-invent it wrong over and over again.

Another poster I think was right: ntpd (and the underlying OS) hides a
lot of these sins. Either by just twitterpating at the leapsecond in
some way (time stands still, time jumps back a little, etc), or for a
period of time around the leapsecond (by sticking its fingers in its
ears, singing lalala and changing the size of a second to get through
it a millisecond at a time).

Warner
Received on Sun Dec 31 2006 - 11:46:49 PST