In linguistics, TUTT (always written as uppercase T plus uppercase UTT in subscript) is an abbreviation for the time of utterance, the primary temporal reference in establishing tense.
Grammatical tense represents the contrast between two measurements along the timeline of an utterance, with one of those measurements being the time of utterance TUTT (the time at which the actual utterance is made). TUTT is always the primary point of reference for tense. There are three additional references to which TUTT can be contrasted: TAST — the time of assertion, TCOM — the time of completion, and TEVL — the time of evaluation; these are secondary references. The type used for the secondary reference is determined by aspect and type of utterance.