Win8 Strawberry 5.30.3.1 (64)  Mon 05/09/2022  0:45:49
C:\@Work\Perl\monks
>perl

use strict;
use warnings;

use JSON;
use Data::Dump qw(dd);

my $json_string = <<'EOJ';
[["urlkey","timestamp","original","mimetype","statuscode","digest","length"],
 ["org,archive)/", "19970126045828", "http://www.archive.org:80/",
  "text/html", "200", "Q4YULN754FHV2U6Q5JUT6Q2P57WEWNNY", "1415"],
 ["org,archive)/", "19971011050034", "http://www.archive.org:80/",
  "text/html", "200", "XAHDNHZ5P3GSSSNJ3DMEOJF7BMCCPZR3", "1402"],
 ["org,archive)/", "19971211122953", "http://www.archive.org:80/",
  "text/html", "200", "XAHDNHZ5P3GSSSNJ3DMEOJF7BMCCPZR3", "1405"]]
EOJ

my $ar_decoded_json = decode_json $json_string;
# dd $ar_decoded_json;  # for debug

my $first_timestamp = $ar_decoded_json->[1][1];
print "'$first_timestamp' \n";

^Z
'19970126045828'