A fundamental component of immersive computer-based tutoring systems is a virtual world that is true to life physically and socially. To simulate this pedagogical stage with the focus on its spatio-temporal aspects we develop novel knowledge structures and associated functions. This mechanism is used to model the physical world in an omniscient view and individual virtual humans' limited personal views. This development enables the situations involving diverse virtual human residents performing autonomous actions to unfold in historically consistent and spatially (and physically) correct manners through each situation and beyond. Base on this virtual stage the tutoring systems can provide coherent contexts across each student's learning sessions.