bin/53899: mktime gives wrong result in Central timezone

[Nick Triantos]

The following reply was made to PR bin/53899; it has been noted by GNATS.

From: "Nick Triantos" <nick at triantos.com>
To: "'Barry Pederson'" <bp at barryp.org>,
	<FreeBSD-gnats-submit at FreeBSD.org>
Cc:  
Subject: RE: bin/53899: mktime gives wrong result in Central timezone
Date: Sun, 29 Jun 2003 23:47:39 -0700

 I found out the hard way that this is apparently not a bug, but a
 feature.  On *BSD systems, for some weird reason, mktime() does not call
 localtime().  I had submitted a patch to fix this, but it got removed
 because there are apparently some applications that depend on this
 unusual behaviour.
 
 To work around the problem, call localtime() manually.
 
 -Nick
 
 -----Original Message-----
 From: owner-freebsd-bugs at freebsd.org
 [mailto:owner-freebsd-bugs at freebsd.org] On Behalf Of Barry at FreeBSD.org
 Sent: Sunday, June 29, 2003 10:06 AM
 To: FreeBSD-gnats-submit at FreeBSD.org
 Subject: bin/53899: mktime gives wrong result in Central timezone
 
 
 
 >Number:         53899
 >Category:       bin
 >Synopsis:       mktime gives wrong result in Central timezone
 >Confidential:   no
 >Severity:       non-critical
 >Priority:       medium
 >Responsible:    freebsd-bugs
 >State:          open
 >Quarter:        
 >Keywords:       
 >Date-Required:
 >Class:          sw-bug
 >Submitter-Id:   current-users
 >Arrival-Date:   Sun Jun 29 10:10:08 PDT 2003
 >Closed-Date:
 >Last-Modified:
 >Originator:     Barry Pederson
 >Release:        FreeBSD 4.8-RELEASE i386
 >Organization:
 >Environment:
 System: FreeBSD eden.barryp.org 4.8-RELEASE FreeBSD 4.8-RELEASE #0: Sat
 Apr 5 12:35:50 CST 2003
 barryp at eden.barryp.org:/usr/obj/usr/src/sys/BARRYP i386
 
 
 >Description:
 	The mktime function seems to give an incorrect result when the
 timezone
         is set to US Central time.  I first noticed this when running
 Zope3 (Python)
         unittests, but can also demonstrate the problem using Perl.
 
 >How-To-Repeat:
 
         Execute mktime() with the same parameters, but vary the TZ
 enviroment
         variable.  Here is a shell script and a perl script to
 demonstrate:
 
 
 ------ tzdemo.sh -----------
 #!/bin/sh
 
 for tz in 'EST5EDT' 'CST6CDT' 'MST7MDT' 'PST8PDT'
 do
     export TZ=$tz;
     /usr/bin/env perl tzdemo.pl $tz
 done
 ----------------------------
 
 
 
 ------ tzdemo.pl -----------
 #!/usr/bin/env perl
 
 use POSIX;
 
 # An arbitrary unix timestamp and its
 # gmtime() equivalent.
 #
 
 $test_time = 1055176982;
 @test_gm = (2, 43, 16, 9, 5, 103, 1, 159, 0);
 
 # You could also say:
 #
 # @test_gm = gmtime($test_time);
 
 # Convert test time back to a unix timestamp, but since
 # mktime() assumes localtime, the result should vary
 # according to the current timezone setting
 #
 
 $result = mktime(@test_gm);
 
 # Calculate the difference, in hours, between what mktime()
 # came up with for a local value  and the initial GMT time
 # we started with.
 #
 
 $diff = ($result - $test_time) / 3600;
 
 print "$ARGV[0] $result $diff\n";
 ----------------------------
 
 
 The expected output is:
 
   EST5EDT 1055194982 5
   CST6CDT 1055198582 6
   MST7MDT 1055202182 7
   PST8PDT 1055205782 8
 
 The actual output I get is:
 
   EST5EDT 1055194982 5
   CST6CDT 1055194982 5
   MST7MDT 1055202182 7
   PST8PDT 1055205782 8
 
 The second line (CST6CDT) should not have the same numbers.
 >Fix:
 >Release-Note:
 >Audit-Trail:
 >Unformatted:
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