What is the optimal way to loop between two dates in Perl?

Question

What is the optimal/clearest way to loop between two dates in Perl? There are plenty of modules on CPAN that deal with such matter, but is there any rule of thumb for iterating between two dates?

Answer 1

For everything that uses Date manipulation DateTime is probably the best module out there. To get all dates between two dates with your own increment use something like this:

#!/usr/bin/env perl
use strict;
use warnings;
use DateTime;

my $start = DateTime->new(
    day   => 1,
    month => 1,
    year  => 2000,
);

my $stop = DateTime->new(
    day   => 10,
    month => 1,
    year  => 2000,
);


while ( $start->add(days => 1) < $stop ) {
    printf "Date: %s\n", $start->ymd('-');
}

This will output:

Date: 2000-01-02
Date: 2000-01-03
Date: 2000-01-04
Date: 2000-01-05
Date: 2000-01-06
Date: 2000-01-07
Date: 2000-01-08
Date: 2000-01-09

Answer 2

These days, most people would recommend using DateTime:

use DateTime;   

my $start = DateTime->new(...); # create two DateTime objects
my $end   = DateTime->new(...);

while ($start <= $end) {
    print $start->ymd, "\n";
    $start->add(days => 1);
}