[tz] tzdb timezone names/identifiers and links

Guy Harris guy at alum.mit.edu
Tue Feb 26 20:14:53 UTC 2019

On Feb 26, 2019, at 11:49 AM, Fred Gleason <fredg at paravelsystems.com> wrote:

> On Tue, 2019-02-26 at 11:06 -0800, Guy Harris wrote:
>> Nothing obliges you to use the tzdb identifiers rather than, say,
>> names that might not require knowing how tzdb region IDs are chosen,
>> e.g. "China" as the name for Asia/Shanghai (and something else, such
>> as Xinjiang or Urumqi, for Xinjiang time),
> That is, unless you are an ethnic Han living in the Western Regions, in
> which case you probably want Asia/Shanghai after all.

Is an ethnic Han living there less likely to realize that "China" is more appropriate than "Xinjiang" or "Urumqi" for them than they are to realize that "Asia/Shanghai" is more appropriate than "Asia/Urumqi"?  If so, why?

> My basic take is this: civil timekeeping is quite complex enough as it
> is, without the arbitrary interposition of yet more layers of
> indirection in the zone indexing. In many (perhaps most?) applications,
> such indirection may be a necessary evil. However, anything that
> increases the overall global complexity of a system imposes a 'tax' of
> its own (both in system resources and in the ease with which the system
> can be modeled and understood in a programmers head). It's well to
> consider this cost in the overall context of the intended use case,
> platform capabilities and intended user audience. To issue a
> categorical imperative like 'tzdb identifiers should *never* be shown
> to users' is to short-circuit this entire delicate design process of
> weighing tradeoffs.

So presumably the tradeoff here is implementation complexity that the programmer's brain has to deal with vs. UI complexity that the end user's brain has to deal with, with the indirection taking away UI complexity for the end user (i.e., having to understand about the notion of tzdb regions and their IDs).

More information about the tz mailing list