$outfolder = sprintf "REPORT_output_%d_%d_%d__%d_%d_%d",
    $year, $mon, $mday, $hour, $min, $sec;

##</code><code>##

$outfolder = sprintf "REPORT_output_%04d_%02d_%02d__%02d_%02d_%02d",
    $year, $mon, $mday, $hour, $min, $sec;

##</code><code>##

REPORT_output_2015_06_01__00_19_42