Perl Past Date How To?

Question

I have a perl script that is getting the current time coming through in a but I am also looking to get the date 45 days prior to the current time as well. Here is what I have:

*already tried using date::calc DHMS which is why the second is formatted the way it is but it keeps returning an error

# get the current time stamp
use POSIX qw( strftime );
my $current_time = strftime("%Y-%m-%d %H:%M:%S", localtime);

print "\n$current_time\n";

# get the date 45 days ago
my $time = strftime("%Y, %m, %d, %H, %M, %S", localtime);

print "\n$time\n\n";

"keeps returning an error": show what you are doing and what error it gives — ysth, Jan 03 '13 at 23:12
After separating the month, day and year into separate variables the Date::Calc method was successful. — Nicholas Anderson, Jan 04 '13 at 04:31

gpojd · Answer 1 · 2013-01-04T00:13:18.187

6

Have you tried DateTime?

my $now = DateTime->now( time_zone => 'local' );
my $a_while_ago = DateTime->now( time_zone => 'local' )->subtract( days => 45 );
print $a_while_ago->strftime("%Y, %m, %d, %H, %M, %S\n");

edited Jan 04 '13 at 00:13

answered Jan 03 '13 at 21:15

gpojd

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Unfortunately DateTime is unavailable to me for this script. Guess I should have declared that in the original question. – Nicholas Anderson Jan 04 '13 at 04:37

score 5 · Accepted Answer · answered Jan 03 '13 at 23:35

5

Preferably use DateTime, DateManip, or Date::Calc, but you can also:

use POSIX 'strftime', 'mktime';

my ($second,$minute,$hour,$day,$month,$year) = localtime();
my $time_45_days_ago = mktime($second,$minute,$hour,$day-45,$month,$year);
print strftime("%Y-%m-%d %H:%M:%S", localtime $time_45_days_ago), "\n";

answered Jan 03 '13 at 23:35

ysth

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In my opinion this solution is harder to read, especially for the person who do the maintenance. I would prefer DateTime's substract. But if no DateTime module is available... – fanlim Jan 06 '13 at 13:22

score 3 · Answer 3 · edited Jan 03 '13 at 23:05

3

use DateTime;

my $now = DateTime->now( time_zone=>'local' );
my $then = $now->subtract( days => 45 );
print $then->strftime("%Y, %m, %d, %H, %M, %S");

Set the time_zone, it's important here.

edited Jan 03 '13 at 23:05

ikegami

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answered Jan 03 '13 at 21:17

alex

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score 2 · Answer 4 · answered Jan 03 '13 at 21:16

2

Here's a simple solution using DateTime:

use strict;
use warnings;
use DateTime;

my $forty_five_days_ago = DateTime->now(time_zone=>"local")->subtract(days => 45);

my $output = $forty_five_days_ago->ymd(", ");

$output .= ", " . $forty_five_days_ago->hms(", ");

print "$output\n";

answered Jan 03 '13 at 21:16

2

`$output = $forty_five_days_ago->strftime("%Y, %m, %d, %H, %M, %S");` would also do the trick. – ikegami Jan 03 '13 at 23:04

Perl Past Date How To?

4 Answers4