[tz] zic changes (2/2)

Random832 random832 at fastmail.com
Thu Mar 3 05:38:55 UTC 2016


On Wed, Mar 2, 2016, at 21:47, Paul Eggert wrote:
> Guy Harris wrote:
> 
> > The same, of course, applies to PST8PDT and so on; it's not as if the "+" is somehow magical.
> 
> Yes.
> 
> > "Typo" as in "the string 'stdoffset[dst[offset][,start[/time],end[/time]]]' was intended to be 'stdoffset[dst[offset],start[/time],end[/time]]', but somebody accidentally put the square brackets in wrong", so that the you can omit everything after "stdoffset", or you can have "dst..." and omit the offset and/or the end times, but if you specify "dst" you can't omit the start and end values"?
> 
> Yes.  The idea is that if you put in the dst substring, you must also
> append 
> rules.  Otherwise there are no rules.

Er...

As far as I know, the documented behavior of tzcode itself is to use the
DST rules specified in the file "posixrules" (by default an alias for
America/New_York) - I had assumed that glibc did the same. Are you
saying that the _actual intent_ of the POSIX committee was to forbid the
use of the traditional System III timezone format, rather than allowing
it (as the brackets imply) and having the rules be
implementation-defined?

The placement of brackets matches the not-entirely-nonsensical idea of
"Allow both the System V format and the new committee-invented format"
so closely that it's hard to believe that that wasn't, at least, the
understanding of the person who typeset the document, even if it wasn't
the intent of the committee. A mere typo, on the other hand, likely
wouldn't have resulted in balanced brackets.


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