WordPress/wp-includes/date.php

<?php
/**
 * Class for generating SQL clauses that filter a primary query according to date.
 *
 * This file is deprecated, use 'wp-includes/class-wp-date-query.php' instead.
 *
 * @deprecated 5.3.0
 * @package WordPress
 */

_deprecated_file( basename( __FILE__ ), '5.3.0', WPINC . '/class-wp-date-query.php' );

/** WP_Date_Query class */
require_once ABSPATH . WPINC . '/class-wp-date-query.php';