Use of Filters

Please activate boombox-child theme ( you can find it in the zip package downloaded from Envato ), and add following code to functions.php file within boombox-child theme:

/**
 * Px-Lab Support
 * Edit post date format
 * @param string $date Current date
 * @param string $difference The time difference
 *
 * @return string
 */
function boombox_child_edit_post_date( $date, $difference ) {
    $date = 'AGO-IN-ARABIC ' . $difference;
    return $date;
}
add_filter( 'boombox_post_date', 'boombox_child_edit_post_date', 10, 2 );
/**
 * -/end Px-Lab Support
 */

Please note: do not forget to replace AGO-IN-ARABIC with the correct text in your language in the code above.