How does Codeigniter's sess_time_to_update work

Question

based on the following question/answer CodeIgniter session class not working in Chrome

I had the problem where people are unable to login to my website from another

Answer 1

The sess_time_to_update setting is how often the session details (such as last activity) are updated. The default is every 5 minutes (300 seconds) and a new session ID will be generated. This would reset the expiration date based on the sess_expiration setting.

I would suggest keeping the sess_time_to_update at the default (or lower) as that would keep the user session alive longer since the session expiration would keep getting reset. The only setting that may need to remain high would be sess_expiration, that is unless you can determine the users timezone.

There are a couple of ways you could try to determine the users timezone. One would be Javascript (Example: Client Side Timezone Offsetting) or you could try using PHP's GEOIP Methods.