Wordpress remember me cookie lifetime

remember-me-for-one-year.php

<?php 

/**
* Hook on auth_cookie_expiration
* The code goes in your theme/child theme functions.php
* You can also use this plugin: https://wordpress.org/plugins/code-snippets/
*/
add_filter ( 'auth_cookie_expiration', 'ywp_change_remember_me' );
function ywp_change_remember_me( $expire ) {
    return YEAR_IN_SECONDS;
}