er-post-password-expires.php

<?php

/*
Plugin Name: ER Post Password Expires
Plugin URI: https://squareone.software
Description: Sets the expiration of a post/page password protected page
Version: 1.0.0
Author: Elliott Richmond
Author URI: https://squareone.software
Text Domain: er-post-password-expires
*/


/**
 * Filters post password cookie.
 *
 * Defaults to 10 days from point of login. For session cookie, return 0.
 *
 * @since 3.7.0
 *
 * @param int $expires The expiry time, as passed to setcookie().
 */
add_filter( 'post_password_expires', 'wperss_custom_post_password_expires' );
function wperss_custom_post_password_expires( $expires ) {
    return time() + 300; // Expire in 300 seconds, adjust to order
}
?>