date_format.pl

#!/usr/bin/env perl

use strict;
use warnings;
use Text::ASCIITable;

my $t = Text::ASCIITable->new;

my @lines = <STDIN>;

my $heading = shift @lines;
chomp $heading;

$t->setCols(split '\t', $heading);

for my $line ( @lines ) {
    $line =~ s/(20\d{2})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})\t/$1-$2-$3 $4:$5:$6\t/g;
    $line =~ s/(20\d{2})(\d{2})(\d{2})\t/$1-$2-$3\t/g;
    $t->addRow(split '\t', $line);
}

print $t;

exit;