Gavin Lucas has returned to the theme of archaeological time, which has long interested him, and, in this paper, to contemporaneousness in archaeology. For a historian, contemporaneousness is a straightforward matter. The First World War and the Russian Revolution, for example, are considered contemporaneous because the two events took place during the same period of time. Both significantly influenced the course of 20th-century history and influenced each other as well. But for an archaeologist, the very notion of chronology is fundamentally problematic. We date an archaeological object or feature on the basis of morphological attributes that allow us to estimate the time during which it was created. In other words, a historical date (the actual date when some vestige came to be) corresponds, in archaeology, to a probable length of time. Archaeological time floats.