Scheduling algorithms for real-time systems can be characterized in various ways, one of the most important ones of which is the underlying task model. Many concepts of real-time scheduling relate to either properties local to a single task or constraints imposed onto a task by its context within an application. In terms of real-time applications, task-local properties usually refer to a task-local timeline, whereas contextimposed constraints can frequently be expressed by a clock global throughout the real-time application. This work introduces a paradigm which allows to separate the two aspects of time inherent in an application. Problems under this paradigm are specified in a hierarchical task model. Finally, a suggestion for a dynamic scheduling algorithm based on this specification methodology is made to demonstrate its feasibility.