Session expiration different on local dev than live

You need to tell us what version of CodeIgniter that you are using for us to really help you.

From what you said it sounds like it may be a timezone setting.

Thank you for your reply. It's 2.0.2. 
Could you explain further? Yes, I am in the US and the live server is in the UK, but why would that explain the 10 min exp vs. 1 year? And where is that even set?