1. Yes:

my @t = ( localtime(time) )[ reverse( 3 .. 5 ) ]; #get year month and 
+day from current localtime
$t[0] += 1900; # see localtime doc for details
$t[1]++; # see localtime doc for details
my $savedir = '/folder/name/' . sprintf( '%04d%02d%02d', @t );
say $savedir;
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/folder/name/20160725
[download]

2. In this case the scalar $savedir should be an string, so you have to quote it. (e.g. my $savedir = 'foldername';