Thomas Pynchon’s novels have plenty to say about time. V. (1963) and Mason & Dixon (1997), in different ways, put history in conversation with the author’s own time. Time travel crops up in Vineland (1990), Against the Day (2006) and Bleeding Edge (2013). Gravity’s Rainbow (1973) pits determinism against randomness and novelty. Different ways of thinking about time are prominent in critical readings of Pynchon: This chapter describes some arguments about time as both theme and principle of narrative organization, and highlights some telling details of the novels themselves. Against the Day is important for readers interested in Pynchon and time because it is set in the closing decades of the nineteenth century and the early part of the twentieth, when H. G. Wells’ The Time Machine and influential contributions to the philosophy of time by Henri Bergson and William James appeared, Futurists and Cubists transformed the way art depicts time and movement, and modernism began to change how literature represents time.