From jasonn@noble.vservers.com

Hello. i'm not sure if this is the correct place to report this, if it
is not, please let me know the correct process.

I have discovered a possible bug with the Time​::Local​::timelocal
functionality. I've tested this problem on Linux, BSD and Solaris, they
all seem to have the same problem. I'm running 5.004_04 on BSDI,
5.005_03 on Solaris and 5.6.0 on Red Hat Linux.

The problem seems to only occur using the date 4/2/2000 at 1​:00am and
2​:00am. What I'm doing is using the timelocal function to get a UNIX
date stamp for 4/2/2000 1​:00​:00 and 4/2/2000 1​:59​:59. It correctly
generates this stamp, but when I tell it to do it for 2​:00​:00 and
2​:59​:59, it generates the unix time stamp for 1​:00​:00 and 1​:59​:59
respectively.

I've tried narrowing it down to see what the problem could be, and it
doesn't seem to be a leap year issue (2004 and 1996 work) or a year 2000
issue, as 4/2/1999 works.

Thanks for any light you can shed on the subject.

Jason

--
Jason Noble <jasonn@​noble.vservers.com>
UNIX Administration Developer
HostPro

Reproduction​:
#!/usr/local/bin/perl

use Time​::Local;

$curr_month = 0;
$curr_day = 0;
$curr_year = 0;

  # Don't forget it's 0-11, so 3 is April
  $curr_month = 3;
  $curr_day = 2;
  $curr_year = 100;
  $begin_time = timelocal(0,0,1,$curr_day,$curr_month,$curr_year);

  $end_time = timelocal(59,59,1,$curr_day,$curr_month,$curr_year);

  @​tmp = localtime($begin_time);
  @​tmp2 = localtime($end_time);
  print "Date​: $curr_month $curr_day $curr_year\tBegin​:
$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
  print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";
  $begin_time = timelocal(0,0,2,$curr_day,$curr_month,$curr_year);

  $end_time = timelocal(59,59,2,$curr_day,$curr_month,$curr_year);

  @​tmp = localtime($begin_time);
  @​tmp2 = localtime($end_time);
  print "Date​: $curr_month $curr_day $curr_year\tBegin​:
$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
  print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";

Output​:
[jasonn@​ratbert perl-5.6.0]$ /tmp/tmp.pl
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
[jasonn@​ratbert perl-5.6.0]$

From @tamias

On Thu, Jun 15, 2000 at 12​:31​:25PM -0700, Jason Noble wrote​:

The problem seems to only occur using the date 4/2/2000 at 1​:00am and
2​:00am. What I'm doing is using the timelocal function to get a UNIX
date stamp for 4/2/2000 1​:00​:00 and 4/2/2000 1​:59​:59. It correctly
generates this stamp, but when I tell it to do it for 2​:00​:00 and
2​:59​:59, it generates the unix time stamp for 1​:00​:00 and 1​:59​:59
respectively.

Daylight Savings Time began at 2am on April 2nd this year.

Ronald

From [Unknown Contact. See original ticket]

I'd suspect it has something to do with DST, and the fact that there IS no
04-02-2000-02​:00 in the US. (presuming you're in the US)​:

#!/usr/local/bin/perl
use Time​::Local;
$t = timelocal(0,0,1,2,3,100);
print "$t ", scalar(localtime($t)), "\n";
$t = timelocal(59,59,1,2,3,100);
print "$t ", scalar(localtime($t)), "\n";
$t++;
print "$t ", scalar(localtime($t)), "\n";

$ perl testdst.pl
954666000 Sun Apr 2 01​:00​:00 2000
954669599 Sun Apr 2 01​:59​:59 2000
954669600 Sun Apr 2 03​:00​:00 2000

At 12​:31 PM 6/15/00 -0700, Jason Noble wrote​:

Hello. i'm not sure if this is the correct place to report this, if it
is not, please let me know the correct process.

I have discovered a possible bug with the Time​::Local​::timelocal
functionality. I've tested this problem on Linux, BSD and Solaris, they
all seem to have the same problem. I'm running 5.004_04 on BSDI,
5.005_03 on Solaris and 5.6.0 on Red Hat Linux.

The problem seems to only occur using the date 4/2/2000 at 1​:00am and
2​:00am. What I'm doing is using the timelocal function to get a UNIX
date stamp for 4/2/2000 1​:00​:00 and 4/2/2000 1​:59​:59. It correctly
generates this stamp, but when I tell it to do it for 2​:00​:00 and
2​:59​:59, it generates the unix time stamp for 1​:00​:00 and 1​:59​:59
respectively.

I've tried narrowing it down to see what the problem could be, and it
doesn't seem to be a leap year issue (2004 and 1996 work) or a year 2000
issue, as 4/2/1999 works.

Thanks for any light you can shed on the subject.

Jason

--
Jason Noble <jasonn@​noble.vservers.com>
UNIX Administration Developer
HostPro

Reproduction​:
#!/usr/local/bin/perl

use Time​::Local;

$curr_month = 0;
$curr_day = 0;
$curr_year = 0;

\# Don't forget it's 0\-11\, so 3 is April
$curr\_month = 3;
$curr\_day = 2;
$curr\_year = 100;
    $begin\_time = timelocal\(0\,0\,1\,$curr\_day\,$curr\_month\,$curr\_year\);

    $end\_time = timelocal\(59\,59\,1\,$curr\_day\,$curr\_month\,$curr\_year\);

    @​tmp = localtime\($begin\_time\);
    @​tmp2 = localtime\($end\_time\);
    print "Date​: $curr\_month $curr\_day $curr\_year\\tBegin​:

$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";
$begin_time = timelocal(0,0,2,$curr_day,$curr_month,$curr_year);

    $end\_time = timelocal\(59\,59\,2\,$curr\_day\,$curr\_month\,$curr\_year\);

    @​tmp = localtime\($begin\_time\);
    @​tmp2 = localtime\($end\_time\);
    print "Date​: $curr\_month $curr\_day $curr\_year\\tBegin​:

$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";

Output​:
[jasonn@​ratbert perl-5.6.0]$ /tmp/tmp.pl
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
[jasonn@​ratbert perl-5.6.0]$

From [Unknown Contact. See original ticket]

This brings up something else though... the statement from the documentation​:

"These routines are quite efficient and yet are always
  guaranteed to agree with localtime() and gmtime()."

Is not entirely accurate, because​:

@​foo = (0,0,2,2,3,100);
timelocal(@​foo) != (localtime( timelocal(@​foo) ));

Perhaps instead of "fudging" there, it should determine if it's in the
'skipped hour' and return undef or -1 or something 'special' to indicate
"you've requested a local time which didn't exist".

D

From [Unknown Contact. See original ticket]

On Thu, 15 Jun 2000, Derek J. Balling wrote​:

This brings up something else though... the statement from the documentation​:

"These routines are quite efficient and yet are always
guaranteed to agree with localtime() and gmtime()."

Is not entirely accurate, because​:

@​foo = (0,0,2,2,3,100);
timelocal(@​foo) != (localtime( timelocal(@​foo) ));

Perhaps instead of "fudging" there, it should determine if it's in the
'skipped hour' and return undef or -1 or something 'special' to indicate
"you've requested a local time which didn't exist".

Hey, I thought we were DONE with the string decrement thread.

:-)

John.

From [Unknown Contact. See original ticket]

That makes total sense now. Sorry I didn't come up with that on my own.

Jason

--
Jason Noble <jasonn@​noble.vservers.com>
UNIX Administration Developer
HostPro

"Derek J. Balling" wrote​:

I'd suspect it has something to do with DST, and the fact that there IS no
04-02-2000-02​:00 in the US. (presuming you're in the US)​:

#!/usr/local/bin/perl
use Time​::Local;
$t = timelocal(0,0,1,2,3,100);
print "$t ", scalar(localtime($t)), "\n";
$t = timelocal(59,59,1,2,3,100);
print "$t ", scalar(localtime($t)), "\n";
$t++;
print "$t ", scalar(localtime($t)), "\n";

$ perl testdst.pl
954666000 Sun Apr 2 01​:00​:00 2000
954669599 Sun Apr 2 01​:59​:59 2000
954669600 Sun Apr 2 03​:00​:00 2000

At 12​:31 PM 6/15/00 -0700, Jason Noble wrote​:

Hello. i'm not sure if this is the correct place to report this, if it
is not, please let me know the correct process.

I have discovered a possible bug with the Time​::Local​::timelocal
functionality. I've tested this problem on Linux, BSD and Solaris, they
all seem to have the same problem. I'm running 5.004_04 on BSDI,
5.005_03 on Solaris and 5.6.0 on Red Hat Linux.

The problem seems to only occur using the date 4/2/2000 at 1​:00am and
2​:00am. What I'm doing is using the timelocal function to get a UNIX
date stamp for 4/2/2000 1​:00​:00 and 4/2/2000 1​:59​:59. It correctly
generates this stamp, but when I tell it to do it for 2​:00​:00 and
2​:59​:59, it generates the unix time stamp for 1​:00​:00 and 1​:59​:59
respectively.

I've tried narrowing it down to see what the problem could be, and it
doesn't seem to be a leap year issue (2004 and 1996 work) or a year 2000
issue, as 4/2/1999 works.

Thanks for any light you can shed on the subject.

Jason

--
Jason Noble <jasonn@​noble.vservers.com>
UNIX Administration Developer
HostPro

Reproduction​:
#!/usr/local/bin/perl

use Time​::Local;

$curr_month = 0;
$curr_day = 0;
$curr_year = 0;

\# Don't forget it's 0\-11\, so 3 is April
$curr\_month = 3;
$curr\_day = 2;
$curr\_year = 100;
    $begin\_time = timelocal\(0\,0\,1\,$curr\_day\,$curr\_month\,$curr\_year\);

    $end\_time = timelocal\(59\,59\,1\,$curr\_day\,$curr\_month\,$curr\_year\);

    @​tmp = localtime\($begin\_time\);
    @​tmp2 = localtime\($end\_time\);
    print "Date​: $curr\_month $curr\_day $curr\_year\\tBegin​:

$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";
$begin_time = timelocal(0,0,2,$curr_day,$curr_month,$curr_year);

    $end\_time = timelocal\(59\,59\,2\,$curr\_day\,$curr\_month\,$curr\_year\);

    @​tmp = localtime\($begin\_time\);
    @​tmp2 = localtime\($end\_time\);
    print "Date​: $curr\_month $curr\_day $curr\_year\\tBegin​:

$begin_time\t$tmp[2]​:$tmp[1]​:$tmp[0]";
print "\tEnd​: $end_time\t$tmp2[2]​:$tmp2[1]​:$tmp2[0]\n";

Output​:
[jasonn@​ratbert perl-5.6.0]$ /tmp/tmp.pl
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
Date​: 3 2 100 Begin​: 954666000 1​:0​:0 End​: 954669599 1​:59​:59
[jasonn@​ratbert perl-5.6.0]$