In this paper a model for temporal references in natural language (NL) is studied and a Prolog implementation of it is presented. This model is intended to be a common framework for semantic analysis of verb tenses and temporal adverbial phrases. The time model choosen was based on time intervals and temporal relations. The notion of “proposition type” and temporal concepts of tense, aspect, duration, location and iteration were represented as temporal relations between some special time intervals and temporal quantifiers over time intervals. The implementation consisted in extending an existing semantic analyser based on the approach to NL semantics of [Por Fil 84]. Area: Natural Language Understanding