This paper is directed toward a traditional problem in the analysis of texts, that of finding meaningful linguistic units that are larger than a sentence and smaller than the text itself. Two principles are given for finding extended temporal structures based on the temporal expressions that occur in sentences: a sentence can be captured to form part of an extended temporal structure, just in case it does not have a deictic adverbial; and a sentence can be captured only if it has the same tense as its captor. Problematic cases are discussed and judged not to present insuperable difficulties for the principles. However, based on temporal expressions only, the principles do not explain the way extended temporal reference actually works in texts. It is concluded that, in general, textual constructions cannot be accounted for with principles that are sentence-based and syntactically oriented. (Author/JB)