Can you give me a hint WHERE I go to mess with the time limit?
in \libs\html.inc.php
find:
if (!isset($config['COOKIE_LIFETIME'])) $config['COOKIE_LIFETIME'] = 604800;
if ($config['COOKIE_LIFETIME'] > 604800) $config['COOKIE_LIFETIME'] = 604800;
replace with:
if (!isset($config['COOKIE_LIFETIME'])) $config['COOKIE_LIFETIME'] = 604800;
if ($config['COOKIE_LIFETIME'] > 2592000) $config['COOKIE_LIFETIME'] = 2592000;
86400 = 24hrs
604800 = 7 days (Default for UBBT 7.5.8)
2592000 = 30 days (What Gizmo and I both recommend)
31536000 = 365 days (Default for UBBT 7.5.7 and prior)
Then, go to:
Control Panel > Primary Settings > Advanced Options
Edit "Cookie Expiration Time:" to whatever you want, but the max will be no more than what you've just modified html.inc.php to be.