How long does a user session lasts.

If a simulation is running in the background, it appears that your session can still be closed before the simulation finished. Should that be the case?

Or rather may be a simulation is kept in a state_so_far and queued up. Which I think what it tires to do. However I am unsure whether the simulation state so far is kept or revert back to when the user logs in again (i might be wrong). Instead the simulation seems to start from the start date. At least that is the feeling I get from the Status (i.e. progress) header.