#!/usr/bin/perl
use strict;
use warnings;
use Date::Manip;
use feature 'say';

my $datestr = ParseDate("today");
say UnixDate($datestr,"Year:%Y Month: %b Day: %e");

my $deltastr = ParseDateDelta("14 months ago");
say UnixDate($deltastr,"Year:%Y Month: %b Day: %e");

say Date_Cmp($datestr, $deltastr); # gives you the difference
say Date_Cmp($datestr, $datestr); # gives you no difference

__END__

$ perl test.pl
Year:2018 Month: Aug Day:  6
Year:2017 Month: Jun Day:  6
1
0