Code-Snippets-Functions/Execute a function on a child site/WooCommerce/add-order-date-time-order-email-notifications.txt

add_action( 'woocommerce_email_order_details', 'custom_processing_order_notification', 1, 4 );
function custom_processing_order_notification( $order, $sent_to_admin, $plain_text, $email ) {
    // Only for processing email notifications to customer
    if( ! 'customer_processing_order' == $email->id ) return;

    $date_modified = $order->get_date_modified();
    $date_paid = $order->get_date_paid();

    $date =  empty( $date_paid ) ? $date_modified : $date_paid;

    echo sprintf( '<p>Order NO. %s (placed on <time>%s</time>)</p>',
        $order->get_order_number( ),
        $date->date("F j, Y, g:i:s A T")
    );
}