The logical approach to temporal reasoning

Temporal reasoning started to be considered as a subject of study in artificial intelligence in the late 1970's. Since then several ways to represent and use temporal knowledge have been suggested. As a result of that, there are several formalisms capable of coping with temporal notions in some way or other. They range from isolated proposals to complex systems where the temporal aspect is used together with other important features for the task of modelling an intelligent agent. The purposes of this article are to summarize logic-based temporal reasoning research and give a glance on the different research tracks envisaging future lines of research. It is intended to be useful to those who need to be involved in systems having these characteristics and also an occasion to present newcomers some problems in the area that still waits for a solution.