Look in WebServer for a generated line;
s_web._SitesQueue.Defaults.SessionExpiryAfterHS =
(the number after the = is the time you set on the Advanced tab for the "session timeout".
This number is in hundreths of a second.
The template limits you to 24:00, but you can set the number higher in code.
A week is
60480000
Cheers
Brice