From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.bugs Subject: bug#26149: SRFI-19 doc erroneously warns about Gregorian reform Date: Wed, 19 Apr 2017 16:42:57 +0200 Message-ID: <878tmwmpam.fsf@igalia.com> References: <20170317235307.GF6518@fysh.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1492613106 18553 195.159.176.226 (19 Apr 2017 14:45:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 19 Apr 2017 14:45:06 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) Cc: 26149@debbugs.gnu.org To: Zefram Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Wed Apr 19 16:45:02 2017 Return-path: Envelope-to: guile-bugs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d0qqo-0004ap-Sz for guile-bugs@m.gmane.org; Wed, 19 Apr 2017 16:44:59 +0200 Original-Received: from localhost ([::1]:48551 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0qqu-0006i9-IU for guile-bugs@m.gmane.org; Wed, 19 Apr 2017 10:45:04 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:34946) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d0qpz-00061Q-En for bug-guile@gnu.org; Wed, 19 Apr 2017 10:44:08 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d0qpv-0002BR-Hs for bug-guile@gnu.org; Wed, 19 Apr 2017 10:44:07 -0400 Original-Received: from debbugs.gnu.org ([208.118.235.43]:58817) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1d0qpv-0002BK-AM for bug-guile@gnu.org; Wed, 19 Apr 2017 10:44:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1d0qpt-00021K-Uq for bug-guile@gnu.org; Wed, 19 Apr 2017 10:44:03 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Andy Wingo Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Wed, 19 Apr 2017 14:44:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 26149 X-GNU-PR-Package: guile X-GNU-PR-Keywords: Original-Received: via spool by 26149-submit@debbugs.gnu.org id=B26149.14926129917696 (code B ref 26149); Wed, 19 Apr 2017 14:44:01 +0000 Original-Received: (at 26149) by debbugs.gnu.org; 19 Apr 2017 14:43:11 +0000 Original-Received: from localhost ([127.0.0.1]:57016 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d0qp4-000203-LM for submit@debbugs.gnu.org; Wed, 19 Apr 2017 10:43:10 -0400 Original-Received: from pb-sasl1.pobox.com ([64.147.108.66]:54453 helo=sasl.smtp.pobox.com) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1d0qp3-0001zv-JZ for 26149@debbugs.gnu.org; Wed, 19 Apr 2017 10:43:09 -0400 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-sasl1.pobox.com (Postfix) with ESMTP id 016C781B3B; Wed, 19 Apr 2017 10:43:06 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=aRuSHtoKWvKddIEy2KcY80kwQXA=; b=cb3Jiq cV3ZpMqS//X2GNfpbA2mQU/X+ud8T3oRliZ/4pBUUsYTxdhiBetblf44QrFlEjzp Tn70mTvLb/XHO2H3yz5ufGe+OSYUxbq/ylrq2BuEs8684vZjVU8zy0LKeDTjpWsN VDW+SNfK4g8P0Fm4Wzz5IllI9Qg0TApe1vZmg= Original-Received: from pb-sasl1.nyi.icgroup.com (unknown [127.0.0.1]) by pb-sasl1.pobox.com (Postfix) with ESMTP id D87D481B3A; Wed, 19 Apr 2017 10:43:05 -0400 (EDT) Original-Received: from rusty (unknown [88.160.190.192]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by pb-sasl1.pobox.com (Postfix) with ESMTPSA id 0243481B39; Wed, 19 Apr 2017 10:43:04 -0400 (EDT) In-Reply-To: <20170317235307.GF6518@fysh.org> (zefram@fysh.org's message of "Fri, 17 Mar 2017 23:53:07 +0000") X-Pobox-Relay-ID: 7F29EC26-250E-11E7-A16B-07D2064AB293-02397024!pb-sasl1.pobox.com X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 208.118.235.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: "bug-guile" Xref: news.gmane.org gmane.lisp.guile.bugs:8749 Archived-At: On Sat 18 Mar 2017 00:53, Zefram writes: > The documentation, near the start of the section on SRFI-19, says > > ! *Caution*: The current code in this module incorrectly extends the > ! Gregorian calendar leap year rule back prior to the introduction of > ! those reforms in 1582 (or the appropriate year in various countries). > ! The Julian calendar was used prior to 1582, and there were 10 days > ! skipped for the reform, but the code doesn't implement that. > ! > ! This will be fixed some time. Until then calculations for 1583 > ! onwards are correct, but prior to that any day/month/year and day of the > ! week calculations are wrong. > > The statements that the code is incorrect in this behaviour are erroneous. > SRFI-19 itself says > > # A Date object, which is distinct from all existing types, represents a > # point in time as represented by the Gregorian calendar as well as by a > # time zone. > > The code is thus correct in always using the Gregorian calendar in > date structures. Per ISO 8601 it is also correct in always using > the Gregorian calendar in string output in that standard's formats. > SRFI-19 isn't explicit about the calendar used as the basis for the > other string output formats, but since the formatting proceeds from a > date structure it seems implied that they should use the same basis as > the date structure. For string input it is explicit that the parseable > numeric formats correspond directly to fields of the date structure. > There is no part of SRFI-19 that looks like it is ever intended to use > the Julian calendar. > > So the code should not be `fixed', and the statements about that and about > incorrectness should be removed from the documentation. It is sensible to > keep an explicit statement about the treatment of the Gregorian reform, > but the decision to use the Gregorian calendar proleptically should be > credited to SRFI-19 (the standard), not to the code. This makes sense to me, FWIW. Andy