Students are mainly left on their own for the entire 20 days. The schedule and daily discipline remains basically the same as it is for normal courses, but we have much more flexibility where we meditate.
Other than the 7 pm group meditation in the hall and the evening discourse, students are free to meditate during the day either in their own rooms, or in the main hall. There are advantages to both. I tended to using the hall during the normal 8 am and 2:30 pm sits. Otherwise, I often meditated in my own room.