A formal framework is proposed for the verification of complex realtime systems, modeled as client-server scheduling systems, using the popular model-checking approach. Model-checking is often restricted by the large statespace of complex real-time systems. The scheduling of tasks in such systems can be taken advantage of for model-checking. Our implementation and experiments corroborate the feasibility of such an approach. Wide-applicability, significant state-space reduction, and several scheduling semantics are some of the important features in our theory and implementation.