Pushing ZEIT (mine is German) once displays VENT OFF. Pushing S/R will activate or disable the fan... Pushing ZEIT again I can set the time I want it to start and store with S/R. Pushing ZEIT even once more I set the time it will shut off (?) and store with S/R. However that was what I thought... But it wonīt shut off at the second preset time. So I havenīt used it incase it will run forever and I forget to turn it off ;) Just used it a few times while I sit in the car and wait and want some fresh air without setting the key in iginition ii and light up everything...