my $secs = 60;
my $time = '23:59:25';

my @time = split /:/, $time, 3;
$time[2] += $secs;

for (my $i = 2; $i >= 1; $i--) {
    if ($time[$i] >= 60) {
         $time[$i] -= 60;
    	 $time[$i-1]++;
    }
}

$time[0] -= 24 if $time[0] >= 24;
$time = join ':', map { length($_) < 2 ? "0$_" : $_ } @time;
print $time;