John Tobey <[EMAIL PROTECTED]> writes:
> On Wed, Aug 09, 2000 at 02:22:22AM +0200, Bart Lateur wrote:
>> date() would be more general, and replace both. You can pass it a time
>> zone, ANY time zone, and it will tell you what time it is in that time
>> zone.
You're proposing embedding the full power of the Olson TZ library into
Perl core. This is a nontrivial amount of data that changes four or five
times a year. I really don't think this is a good idea. Furthermore, the
only time zone database that can actually do this doesn't use the naming
scheme that you're probably used to.
> The JTobey::Date module uses the TZ environment variable (which, I'm
> told, is non-portable), the esoteric POSIX routines tzset and tzname,
> and some functions from the CPAN modules Date::Parse and Date::Format.
It's far worse than non-portable; it's completely insufficient. The POSIX
TZ syntax cannot represent many real time zones. You need the Olson-style
naming scheme which refers to entries in a fairly large external database
of time zones and their current and historic data, not just a wide variety
of bizarre daylight savings changes but time zone changes that often vary
by political whim. (Like Australia fiddling with its daylight savings
rules this year because of the Olympics.)
People in the EU, where there's a standard for daylight savings, and
particularly people in the US, where we haven't changed our rules in quite
a while, often don't realize just how baroque this can get.
> It is designed to give it all an easy OO interface, and to be as
> correct as possible on systems like mine. It is not expected to be
> very fast, portable, or locale-friendly.
> To overcome these problems would be a Herculean task which I simply
> doubt that anyone here is willing to do. Therefore, I oppose the
> notion that Perl 6 will magically handle all this.
> -John
--
Russ Allbery ([EMAIL PROTECTED]) <http://www.eyrie.org/~eagle/>
