timelocal_nocheck: bug or wrongly understood

borisz has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I was under the impression, that timelocal_nocheck can be used with values for month and day larger than days in a month or month in a year, but it works only for days.

I expect the following output:

Sat Jan  1 00:00:00 2005
Sun Jan  1 00:00:00 2006
[download]

but I get this.

use Time::Local qw/timelocal_nocheck/;
print scalar( localtime( timelocal_nocheck( 0,0,0,1,0,5 )) ), "\n";
print scalar( localtime( timelocal_nocheck( 0,0,0,1,12,5 )) );
__OUTPUT__
Sat Jan  1 00:00:00 2005
Sat Jan  1 00:00:00 2005
[download]

Boris

Comment on timelocal_nocheck: bug or wrongly understood Select or Download Code

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Re: timelocal_nocheck: bug or wrongly understood by blokhead (Monsignor) on Nov 28, 2005 at 17:30 UTC
The pod says (emphasis added): `# The 365th day of 1999 print scalar localtime timelocal_nocheck 0,0,0,365,0,99; # The twenty thousandth day since 1970 print scalar localtime timelocal_nocheck 0,0,0,20000,0,70; # And even the 10,000,000th second since 1999! print scalar localtime timelocal_nocheck 10000000,0,0,1,0,99;` [download] Your mileage may vary when trying these with minutes and hours, and it doesn't work at all for months. I wonder if there is a technical reason for this. Perhaps it's because months aren't the same size, while days, hours, minutes, and seconds are almost always the same size. Even so, its current behavior still seems strange.. at least it could try to do something reasonable with months > 12 instead of reducing mod 12 as it does now. blokhead	[reply] [d/l]
Re: timelocal_nocheck: bug or wrongly understood by ikegami (Patriarch) on Nov 28, 2005 at 19:06 UTC
The bug is easily fixable. Change: `sub _daygm { $_[3] + ($Cheat{pack("ss",@_[4,5])} \|\|= do { my $month = ($_[4] + 10) % 12; my $year = $_[5] + 1900 - $month/10; 365$year + $year/4 - $year/100 + $year/400 + ($month306 + 5)/10 +- $Epoc }); }` [download] to `sub _daygm { $_[3] + ($Cheat{pack("ss",@_[4,5])} \|\|= do { my $month = ($_[4] + 10) % 12; my $year = $_[5] + 1900 + ($_[4] + 10) / 12 - 1; 365$year + $year/4 - $year/100 + $year/400 + ($month306 + 5)/10 +- $Epoc }); }` [download] My test: Read more... (1119 Bytes) I created a ticket.	[reply] [d/l] [select]
Re: timelocal_nocheck: bug or wrongly understood by ikegami (Patriarch) on Nov 28, 2005 at 18:34 UTC
Interestingly, older versions give: `Sat Jan 1 00:00:00 2005 Can't handle date (0, 0, 0, 1, 12, 105) at script.pl line 3` [download] This is with the Time::Local that came with Perl 5.6.1. No version is specified in the .pm.	[reply] [d/l]
Re: timelocal_nocheck: bug or wrongly understood by gu (Beadle) on Nov 28, 2005 at 19:00 UTC
At first glance I don't see why something like `if ($month > 11) { my $gap = int($month/12) ; $year += $gap ; $month -= 12*$gap ; }` [download] out of the `unless ($Options{no_range_check})` braces in `Local.pm` `timegm` function shouldn't make it, at least for months over 11... For negative months it's a bit more complex... Gu	[reply] [d/l] [select]
Re: timelocal_nocheck: bug or wrongly understood by borisz (Canon) on Nov 29, 2005 at 08:57 UTC
Thanks all, until this is fixed, I use `POSIX::mktime`, where large months are permitted. Boris	[reply]