$a = "abcdefghij";
length($a) lt 2  ==>  "10" lt "2"  ==>  true
$a = "0$a";
length($a) lt 2  ==>  "11" lt "2"  ==>  true
...
$a = "0$a";
length($a) lt 2  ==>  "20" lt "2"  ==>  false

##</code><code>##

my $min = (localtime)[1];
$min = sprintf('%02d', $min);