Работа с датой

#!/usr/bin/perl
 
use strict;
use warnings;
use Date::Calc qw(Today_and_Now Add_Delta_Days);
use Time::Local;
 
my $diff_day = -3;
 
main();
 
#================================================================
sub get_current_time
{
    return time();
}
 
#================================================================
sub unix_time_to_date
{
    my $unix_time = shift;
    
    return gmtime($unix_time);
}
 
#================================================================
sub delta_date
{
    my ($current_year, $current_month, $current_day, $current_hour, $current_min, $current_sec) = Today_and_Now();
 
    my ($year, $month, $day) = Add_Delta_Days($current_year, $current_month, $current_day, $diff_day);
 
 
    my $date_unix = timegm($current_sec, $current_min, $current_hour, $day, $month-1, $year);
 
    print "Diff date (unix): $date_unix\n";
    print "Normal date: " . unix_time_to_date($date_unix) . "\n";
    print "==================================\n";  
}
 
#================================================================
sub main
{
    system('clear');
 
    print "==================================\n";
    print 'Current date (unix): ' . get_current_time() . "\n";
    print 'Current date: ' . unix_time_to_date(get_current_time()) . "\n";
    print "==================================\n";
 
    delta_date();
}

($year,$month,$day, $hour,$min,$sec) = Today_and_Now([$gmt]);

use Date::Calc qw(Add_Delta_Days Localtime);

my ($current_year, $current_month, $current_day, $current_hour, $current_min, $current_sec) = Localtime();