Time plays a major role in clinical diagnosis, prediction, and therapy planning. Actually, time-oriented clinical data are a major decision making factor for many clinical guidelines. An important research problem is how to model guideline concisely and clearly so that temporal constraints can be implemented in guideline-based decision support systems in a straightforward manner. The contributions of this paper are twofold: (1) to develop a temporal query language for medical domain-TempoCom (Temporal Comprehension), which provides comprehensive yet concise expressions for querying temporal medical data and (2) to extend the clinical practice guideline development tool-CPGen (Clinical Practice Guideline application Generator) with the capability of supporting temporal decision rules expressed in TempoCom. With the extended CPGen, one can develop temporal guideline-based decision support systems for clinical treatment rapidly.