PHP Sessions

I have been programming in PHP for several years. I have a new client that says the timeout on the sessions is way too short. IE he logs in and wants to stay logged in for alot longer than the default 30ish minutes.

Without going into huge detail, what variable do I set to make this longer?

Is it "wait timeout" ? It's currently set to 28800 which would be 8 hours if those are seconds so I assume this isn't it.

This client wants it to be one hour anyone have any ideas? I have went through docs for hours and can't find what would change this.

Thanks in advance.

Xunil