Question

I was trying to determine a good way to calculate a previous date based on how many weeks I would want to go back. Today is 7/19/2011, so if I wanted to go back 5 weeks what would be the best way to determine what that date would be?

Answer 1

DateTime::Duration is your friend there:

use strict;
use warnings;
use 5.010;

use DateTime;

my $now = DateTime->now(time_zone => 'local');
my $five_weeks = DateTime::Duration->new(weeks => 5);
my $five_weeks_ago = $now - $five_weeks;

say "Five weeks ago now it was $five_weeks_ago";

Notice that it lets you specify the duration in the units of the problem.