open OUT,'>','products.txt' or die "$!";
my @d = (0,31,28,31,30,31,30,31,31,30,31,30,31);
for my $p ('0001'..'2000'){
  my $product = "product_$p";
  for my $y (2015..2017){
    $d[2] = ($y % 4) ? 28 : 29;
    for my $m (1..12){
      for my $d (1..$d[$m]){
        my $date = sprintf "%04d-%02d-%02d",$y,$m,$d;
        my $price = int rand(500);
        my $qu    = int rand(90_000);
        print OUT "$date\t$product\t$price\t$qu\n";
      }
    }
  }
}
close OUT;