According to the Domino 8.5 help you can set automatic logout time periods. I have looked in the advanced settings of the ACL properties on the database and also in the website records and cannot find where one sets these values any ideas
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Default logout time period
You can specify a default logout time period to log the Web client off the server after a specified period of inactivity. This forces the cookie that IBM® Lotus® Domino® uses to track the user session to expire. Automatically logging a user off the server prevents others from using the Web client to impersonate a user if the user leaves the workstation before logging off. If you enable session-based name-and-password authentication for a server, users can also append ?logout at the end of a URL to log off a session – for example:
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