 Whatever the process in question is, it seems likely that it is intimately connected with what William Friedman (1990) calls ‘time memory’: that is, memory of when some particular event occurred. That there is a close connection here is entailed by the plausible suggestion that we infer (albeit subconsciously) the duration of an event, once it has ceased, from information about how long ago the beginning of that event occurred. That is, information that is metrical in nature (e.g. ‘the burst of sound was very brief’) is derived from tensed information, concerning how far in the past something occurred. The question is how we acquire this tensed information. It may be direct or indirect, a contrast we can illustrate by two models of time memory described by Friedman. He calls the first the strength model of time memory. If there is such a thing as a memory trace that persists over time, then we could judge the age of a memory (and therefore how long ago the event remembered occurred) from the strength of the trace. The longer ago the event, the weaker the trace. This provides a simple and direct means of assessing the duration of an event. Unfortunately, the trace model comes into conflict with a very familiar feature of our experience: that some memories of recent events may fade more quickly than memories of more distant events, especially when those distant events were very salient ones (visiting a rarely seen and frightening relative when one was a child, for instance.) A contrasting account of time memory is the inference model. According to this, the time of an event is not simply read off from some aspect of the memory of it, but is inferred from information about relations between the event in question and other events whose date or time is known.