my $dateTime = $hour.":".$min,":".$sec," ".$mday."/".$mon+1."/".$year+1900."";

##</code><code>##

   my @dateTime = ($hour,":",$min,":",$sec," ",$mday,"/",$mon+1,"/",$year+1900,"");

##</code><code>##

  my $dateTime = sprintf "%02d:%02d:%02d %02d/%02d/%d",
      $hour, $min, $sec,
      $mday, $mon+1, $year+1900;