Keld J|rn Simonsen wrote:
> [...] ISO CD 14652
I just downloaded this draft standard from
http://www.dkuug.dk/JTC1/SC22/WG20/prot
Minor comment:
The date field descriptors in 4.1.5.1 seem to be somewhat incomplete,
and this should in my opinion be revised in cooperation with the ISO C
folks. Below is an excerpt from a mail that I sent already to some ISO
C people like Clive D.W. Feather <clive@demon.net>. A very similar
comment from Paul Eggert (a widely respected POSIX time handling
algorithm implementor) can be found in the archive of the tz mailing
list <ftp://elsie.nci.nih.gov/pub/tzarchive.gz>.
- %V alone is not sufficient to be able to use the ISO week numbering
system. Each week is associated with a year, the year in which the
majority of the days of this week fall, and this is not necessarily
the year in which all days of the weeks fall. For instance: The
week 1999-W52 goes from 1999-12-27 to 2000-01-02, in other
words, the day 2000-01-02 has a week notation of the
form 1999-W52-7. There should be another format descriptor for
the year to which the current ISO week belongs, preferably both
in 4-digit (%G) and 2-digit (%g) form.
If you implement an algorithm for %V, you'll get the value of %G
anyway as a by-product very easily, and therefore it should be
made available to the strftime() user.
- Existing practice: The Olson tzcode package <ftp://elsie.nci.nih.gov/pub/>
contains a widely used strftime() implementation that supports already:
%u ISO 8601 week day number (1 = Monday, 7=Sunday)
%V ISO 8601 week number (01-53)
%G ISO 8601 year of current week, 4-digits
%g ISO 8601 year of current week, 2-digits
Unless there is a good rationale for the characters suggested
by N733, I would suggest to stick with %u instead of %f for the
weekday number, and I hope that you will add %G and %g as used
in the Olson package and Arnold Robbins' strftime version 3.0.
Therefore, if I evaluate on 1977-01-02 the string %G-W%V-%u, I should
get 1976-W53-7, and on 1975-12-29 I should get 1976-W01-1.
Markus
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