Re: [PATCHv2] Add support for leap seconds in zoneinfo files

[Szabolcs Nagy <nsz@port70.net>]

* Rich Felker <dalias@aerifal.cx> [2013-12-06 07:50:55 -0500]:
> On Fri, Dec 06, 2013 at 10:37:56AM +0000, Laurent Bercot wrote:
> >  Yes, people using TAI-10 should also be using right/ timezones instead of
> > posix/ ones. That's why TZ as a test is appealing: it ensures consistency.
> > But at that level it's entirely the admin's responsibility to have
> > consistent configuration: leap-second-conscious admins won't mind doing
> > some extra work to have a setting that pleases them.
> 
> The problem with this approach is that an individual user may unset
> $TZ or set it to a POSIX-syntax timezone such as "UTC" on a system
> where the system clock is using TAI-10. Users generally expect this to
> work, and their expectation is justified. Valid scripts might even use
> TZ=UTC as part of their functionality.

this just means the tz data depends on the timescale used

if an admin is willing to do the leapsecond hassle then
putting the "right" files into /usr/share/zoneinfo can
be done as well, TZ=UTC will work

the current practice of using TZ=right/foo is wrong, it
means that gmtime-localtime is not the tzoffset or gmtime
depends on TZ

ie. an admin can choose to set up different timescale, but
then leapseconds and zoneinfo must be configured in the
filesystem accordingly (and regularly updated)