This helper function converts the stringified PDF metadata timestamp into a readable timestamp

pdf_date_to_carbon.php

<?php
use Carbon\Carbon;

/**
 * Converts a PDF metadata timestamp (creation_date, mod_date, etc..) into a Carbon object.
 *
 * @ref http://www.verypdf.com/pdfinfoeditor/pdf-date-format.htm
 * @param $pdf_date
 * @return Carbon
 */
function pdf_date_to_carbon($pdf_date) {
    $pdf_date = str_replace('\'','',str_replace('D:','',$pdf_date));
    return Carbon::createFromFormat('YmdHisO',
        substr($pdf_date,0,19));
}