[tz] Missing functionality (general question) - C11 functions, Localization, etc...

Paul Eggert eggert at cs.ucla.edu
Thu Mar 21 23:47:36 UTC 2013

On 03/21/2013 10:08 AM, random832 at fastmail.us wrote:
> More than this, my main question is - what is the role of tzcode - the
> library functions, that is, not the tools - itself? Is it simply a
> reference implementation, to be used by libc maintainers and integrated
> into their libraries as they see fit? Is it meant to be used as a
> drop-in replacement for the system libc's time functions by application
> developers who need consistent timezone handling?

It can be used either way.

It would be nice if it could support any relevant C11 time features that it
doesn't already support.  The main problem, I expect, has been lack of time.
wcsftime has been low-priority since few non-Microsoft developers care
about wide-character support.  localtime_s, gmtime_s. etc. are not required
by the standard and these functions, like the other C11 Annex K functions
are somewhat controversial, so they've been low priority too.  But if
these functions could be added without much disruption to the existing
code base, I can't imagine anyone would object.

> If it's just meant as a reference implementation, or
> just to support zdump,

It can be used to support zdump, but it's not required for that.
You should be able to build zdump with any reasonably-conforming
implementation of localtime etc.

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