For the S model, everything is controlled through the "trip computer" using the top two buttons in the cluster between the steering wheel and the door. You push the top left button until you see the Settings menu in the bottom center of the dash, then follow the directions. As stjohnh says, the timer is not nearly as sophisticated. No start time, no two separate timers, no settings by day of the week, no timer-associated 80%. But because of the back calculation stjohnh mentioned, the end-only timer can be quite useful.
The 2013 SV and SL have two different ways to set an 80% limit, one of them independent of the timer. The S model has only the one which is independent of the timer. This can be irritating at times. You can't use the timer-override button to temporarily override 80% charging. You have to go in to the settings menu and choose the 100% option. Then you have to remember later to go back into the settings to resume 80% charging.
Ray