a1 Department of Anthropology, Arizona State University, Tempe, AZ 85287, USA
To begin the discussion, I propose distinctions between four archaeological approaches to time. I call these clock time, phase time, social time, and characterization. Main points in the other papers are that Postclassic phases tend to be a century or more earlier than recently thought, that Aztec I may be much earlier than thought, and that there may be considerable temporal overlap among Postclassic phases. The evidence is fairly good for the first of these points, but less clear for the other two—more data are needed. I propose a slightly revised Teotihuacan chronology and mention some issues about the nature of the Teotihuacan to post-Teotihuacan transition.