You want to set the time period for which a user is logged in into the C4C system.
Cloud for Customers All Versions.
As per the current system behavior, you cannot set the time period for which a user can be logged in into the C4C system.
This is the expected system behavior.
If you need this functionality urgently you may contact your implementation manager to help with such request or approach directly at SAP Cloud Service Center (email@example.com).
Note: The services of SAP Cloud Service Center will be charged as packaged services based on fixed prices.
An alternative option will be to check SAP Cloud for Customers Idea's Forum and submit your idea:
Log in, Time period , KBA , LOD-CRM-ADM , Administration UI , Problem