In this paper, a timed modal logic Lc is presented for the specification and verification of real-time systems. Several important results for Lc are discussed. First we address the model checking problem and we show that it is an EXPTIME-complete problem. Secondly we consider expressiveness and we explain how to express strong timed bisimilarity and how to build characteristic formulas for timed automata. We also propose a compositional algorithm for Lc model checking. Finally we consider several control problems for which Lc can be used to check controllability.