Re: [TCLCORE] clock format problem

[Alexandre F. <ale...@gm...>]

On Sat, Aug 10, 2013 at 7:55 PM, Arnulf Wiedemann
<ar...@wi...> wrote:
> Hello,
> A colleague of me has problems with clock format with tclsh8.6 (final
> version):
> % clock format [clock seconds] -timezone :America/Brasilia
> % time zone ":America/Brasilia" not found
>
> nevertheless there exists in lib/tcl8.6/clock.tcl
> 327: {-10800 0 3600 0 2 0 5 2 0 0 0 0 11 0 1 2 0 0 0} :America/Brasilia
>
> what also works is:
> % clock format [clock seconds] -timezone :America/Buenos_Aires
> Wed Aug 07 05:11:42 ART 2013
>
> What is the reason for that problem or what are we doing wrong?

You'll note that the working case (Buenos_Aires) is supported by a
file in tzdata. That file loads a value at key ":America/Buenos_Aires"
of the TZData array.

While your non-working case (Brasilia) has no such file, and none of
the files stores anything in TZData(:America/Brasilia).
What you saw in clock.tcl is a load into a reverse dict WinZoneInfo,
which maps vectors of values to names.
I have no familiarity with [clock] internals, especially what purpose
this reverse mapping serves (and the Win prefix makes me Wince), but
it looks like there is no built-in mechanism to make sure the mapping
is bijective...

-Alex