How to control how long specific member name is logged in?

Found code on your site explaining how to control how long user is logged in. The code is:

add_filter( ‘auth_cookie_expiration’, ‘keep_me_logged_in_for_1_year’ );

function keep_me_logged_in_for_1_year( $expirein ) {

return 31556926; // 1 year in seconds

}

How can I modify the code to make expiration apply to specific member name?

Please respond soon.