karks-session-expiration.php

<?php 

/*
Plugin Name: Karks Session Expiration
Plugin URI: https://www.karks.com
Description: A custom plugin that reduces the life of WordPress user sessions for administrators. It trades a tiny bit of convenience for increased security.
Version: 1.0.1
Author: Eric Karkovack
Author URI: https://www.karks.com
Text Domain: karksessionexp
*/

add_filter( 'auth_cookie_expiration', 'karks_session_cookie_expiration', 10, 3 );

function karks_session_cookie_expiration( $expiration, $user_id, $remember ) {
	
	$user = get_user_by( 'id', $user_id );
	if ( $user && in_array( 'administrator', (array) $user->roles ) ): // Is the user an administrator?
	
		// Set the expiration time to 2 hours from now
		$expiration = 2 * HOUR_IN_SECONDS;
	
	endif;
	
	// Return the modified expiration time
		return $expiration;
}