Code snippet to modify the order date format in documents - By WebToffee( WooCommerce PDF Invoice, Packing Slips, Delivery Notes and Shipping labels (free))

functions.php

<?php //Do not add this line of code
add_filter('wf_pklist_alter_order_date', 'wt_pklist_change_order_date_format', 10, 3);

function wt_pklist_change_order_date_format($order_date, $template_type, $order) {
	if ( is_object( $order ) ) {
		$order_id = is_object($order) ? $order->get_id() : '';
		$order_date_format = 'd/m/y'; 
		$order_date = get_the_date( $order_date_format, $order_id );
	}
 
    return $order_date;
}