 Logics can be used to reason about dynamically changing aspects of the world, and time plays a role in many domains. For instance, the notion of knowledge studied in epistemic logic, the idea of an action underlying logics of agency, or the physical concept of space in spatial logics all bear an intimate relation to time. It is therefore natural to add a temporal dimension to these logics and equip the corresponding languages with temporal operators that are suited to capture the relevant notion of change.