Re: How to get last month date using Date::Calc

[haukex]

use warnings;
use strict;
use Date::Calc qw/Add_Delta_YM/;

sub prevmonth {
    my ($year, $month) = @_;
    my ($newyear, $newmonth, undef)
        = Add_Delta_YM( $year, $month, 1, 0, -1 );
    return [$newyear, $newmonth];
}

use Test::More;

is_deeply prevmonth(2003,8), [2003,7];
is_deeply prevmonth(2004,1), [2003,12];

done_testing;

Update: This is also possible with the core module Time::Piece. If you have a modern browser like the latest Firefox or Chrome, here is a live demo of the following code.

use warnings;
use strict;
use Time::Piece;

while (<>) {
    chomp;
    my $t = Time::Piece->strptime($_, '%m/%Y');
    my $prev = $t->add_months(-1);
    print $prev->strftime('%m/%Y'), "\n";
}