  We present Dynamic Epistemic Temporal Logic, a framework for reasoning about
operations on multi-agent Kripke models that contain a designated temporal
relation. These operations are natural extensions of the well-known "action
models" from Dynamic Epistemic Logic. Our "temporal action models" may be used
to define a number of informational actions that can modify the "objective"
temporal structure of a model along with the agents' basic and higher-order
knowledge and beliefs about this structure, including their beliefs about the
time. In essence, this approach provides one way to extend the domain of action
model-style operations from atemporal Kripke models to temporal Kripke models
in a manner that allows actions to control the flow of time. We present a
number of examples to illustrate the subtleties involved in interpreting the
effects of our extended action models on temporal Kripke models. We also study
preservation of important epistemic-temporal properties of temporal Kripke
models under temporal action model-induced operations, provide complete
axiomatizations for two theories of temporal action models, and connect our
approach with previous work on time in Dynamic Epistemic Logic.
