This book grew out of a short paper, Linguistics in the Time Cycle, in which we sketched a single conjecture: that language is not merely something that changes in time but something that is organised by time, across many nestedscales at once. The paper proposed an analogy—language as a temporally regulated system, parallel in its architecture to the way genetic information is expressed, regulated, and inherited through biological time. What began as a set of tables and suggestive parallels seemed to invite a fuller treatment. The present monograph is that treatment. The argument is interdisciplinary by necessity. To speak of language in time is to borrow at once from chronobiology and phonology, from populationgenetics and historical linguistics, from Bakhtin’s poetics of the chronotope andfrom the mathematics of dynamical systems. We have tried throughout to keep the analogy disciplined: an analogy is a scaffold for hypotheses, not a proof, and the value of the LTC framework lies in the concrete, testable questions it makes it natural to ask. Each chapter therefore closes by pointing toward empirical or computational work that could confirm or refute the picture it paints.