Customize the sort by drop down in WooCommerce

functions.php

<?php
function patricks_woocommerce_catalog_orderby( $orderby ) {
	// Add "Sort by date: oldest to newest" to the menu
	// We still need to add the functionality that actually does the sorting
	$orderby['oldest_to_recent'] = __( 'Sort by date: oldest to newest', 'woocommerce' );

	// Change the default "Sort by newness" to "Sort by date: newest to oldest"
	$orderby["date"] = __('Sort by date: newest to oldest', 'woocommerce');

	// Remove price & price-desc
	unset($orderby["price"]);
	unset($orderby["price-desc"]);

	return $orderby;
}
add_filter( 'woocommerce_catalog_orderby', 'patricks_woocommerce_catalog_orderby', 20 );

// Add the ability to sort by oldest to newest
function patricks_woocommerce_get_catalog_ordering_args( $args ) {
	$orderby_value = isset( $_GET['orderby'] ) ? woocommerce_clean( $_GET['orderby'] ) : apply_filters( 'woocommerce_default_catalog_orderby', get_option( 'woocommerce_default_catalog_orderby' ) );

	if ( 'oldest_to_recent' == $orderby_value ) {
		$args['orderby'] = 'date';
		$args['order']   = 'ASC';
	}

	return $args;
}
add_filter( 'woocommerce_get_catalog_ordering_args', 'patricks_woocommerce_get_catalog_ordering_args', 20 );