NateJacobs

Expires a user’s access to a site after a specified number of days. It uses the user registered date/time and an admin configured number of days to determine when to expire the users access. The administrator can restore a user’s access from the user’s profile page.
There is a filter available for developers to hook into and alter the expiration date of a specific user on the fly during authentication. The filter uae_expiration_date passes the current expiration date and the WP_User object.

User Access Expiration

A user's access to a site is disabled after a specified number of days. The admin can set the number of days since registration to deny access.

John Morris

Do you use the “Remember Me” feature when logging in to your WordPress site? I know I do.
Do you find it annoying when WordPress stops remembering you after a few days? I know I do.
Longer Login is a simple WordPress plugin that remedies this. By default, WordPress automatically 
forgets users after 14 days. This plugin adds an option in your website’s General Settings that 
can change this expiration date. There are numerous options ranging from 1 day to 1 year.
Change the setting, and the next time you, or any user on your site logs in with “Remember Me” checked, 
WordPress will keep them logged in for that specified time.
<h4>How Does It Work?</h4>
To remember users, websites store a small piece of information in your web browser’s memory. 
This token of information is called an <a href="wikipedia.org/wiki/HTTP_cookie" rel="nofollow ugc">HTTP cookie</a>. These 
cookies have an expiration date specified by the website.
By default, WordPress websites have their persistent login cookies expire after 14 days. This plugin 
changes the length of time the cookie will survive. Instead of 14 days after login, you can make the 
cookie live for as long as 1 year after login.

Longer Login ("Remember Me" Extension)

Longer Login allows customizing the length of WordPress' "Remember Me" length. No more automatic logouts every few days!

User Access Expiration vs Longer Login ("Remember Me" Extension)