// https://digwp.com/2023/01/stay-logged-in-to-wordpress/
function shapeSpace_stay_logged_in($expires) {
	
	return 3153600000; // 100 years
	
}
add_filter('auth_cookie_expiration', 'shapeSpace_stay_logged_in');
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<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /homepages/24/d10211197/htdocs/www-gr-01.de/gr-2014/wp-content/themes/gr/functions.php:1) in <b>/homepages/24/d10211197/htdocs/www-gr-01.de/gr-2014/wp-includes/pluggable.php</b> on line <b>1353</b><br />