Overview of Usage CAL

A Usage CAL allows any user, identified or anonymous/unidentified, to access one QlikView document, residing on the server or server cluster to which the Usage CAL is assigned, for one client (for example, the AJAX client, QlikView Desktop, or the Internet Explorer plugin) for a time period of up to 60 minutes per session. If a user exceeds the 60 minute time limitation, the user will have consumed two Usage CALs without any warning being given to the user.   Keep in mind, if a session  only lasts 10 minutes, the Usage Cal is considered to have been consumed and will be placed in quarantine.

If you set session time out over 1 hour and you don't perform any action on the qvw before the 1 hour mark is over, the session is still considered open and will not time out - but the QVS will not consume a CAL. Re-opening the session after the two hour mark is over will then require a 2nd Usage CAL.
i.e
12:00 Open a qvw and take action.
13:00 You left the sheet before then
14:00 You start to operate in the same qvw again.
In this case, QVS has consumed 2 CALs, not 3.

Every 28 days, the Usage CAL is refreshed and the user may once again view a new QlikView document for 60 minutes, using the same Usage CAL. Usage CALs are continuously recharged (at a pace corresponding to 1/28 of the  total  number of Usage CALs assigned to the QlikView Server per day).

For example, you have 74 Usage CALs and all CALs consumed. Then QVS returns 3 Usage CALs per day.