In interface-based design, components are described by a component interface. In contrast to a component description that describes what a component does, a component interface describes how a component can be used, and a well designed component interface provides enough information to decide whether two or more components can work together properly in a system. Real-Time Interfaces expand the idea of interfacebased design to the area of real-time system design, where the term of working together properly refers to questions like: Does the composed system satisfy all requested real-time properties such as delay and throughput constraints? In this work, we extend the theory of Real-Time Interfaces and prove its applicability for the design of systems with hierarchical scheduling. We introduce a component system for interface-based design of systems with mixed FP, RM and EDF scheduling. We then further extend the ability for hierarchic scheduling by introducing server components. The introduced component system with Real-Time Interfaces not only allows interface-based design of complex real-time systems with hierarchical scheduling, but also inherently enables detailed schedulability analysis of such systems.