By default, all Symphony sessions either on the Symphony Desktop Application (SDA) or mobile application, call the /login/refresh_token API once a day via datafeed.
Therefore, as long as the user remains active in any one of the Symphony clients (desktop or mobile), their session will continue to be authorised and they will not be logged out.
The only ways a user will be logged out due to an expired session will be if there is no activity in any Symphony client whatsoever for 14 days. At this point, the user will automatically be logged out and they will need to re-enter their login credentials again to access Symphony.
Additionally, if any cookies or the cache are deleted, the session will then be classed as expired and will be logged out.