(See Mohan Matthen, “The sense of time passed”, at NewAPPS.) Is there a primitive feeling of duration? There are bodily feelings which can stand proxy for the passage of time: they are not perceptions of passage (and so don’t raise questions about the perception of temporally extended objects) but of qualities that change in fairly regular ways with the passage of time (like the level of water in the reservoir of a clepsydra). The bladder fills, the stomach empties: and if the one feels full or the other empty, it must have been some time since the one was emptied and the other filled. Muscles and joints complain about the body’s inactivity, the eyes get fatigued. If there is a primitive “feeling of duration” perhaps it is a sort of “summary” feeling that tracks the aggregate of such feelings…
It is noteworthy that the feeling is associated with the durations of “durable” acts like sitting (as contrasted with “instantaneous” acts like turning one’s attention to a new object). In such cases there are bodily concomitants (and mental: retrospective judgments of fairly brief temporal intervals whose terminus ad quem is the present are determined in part by the number of events that have occurred in the interval [Hicks, Miller, Kinsbourne 1976], as if we had an “event buffer” that fills up with over time as new events are perceived).
Even if there is a feeling associated with the interval of three hours one has been sitting, there aren’t feelings associated with e.g. the interval of two hours that one has also been sitting or with the last five minutes of sitting. The feeling in question is not of duration simpliciter but of the temporal interval of an event that has been interrupted or that has ceased. It’s not as if the perception of passage consisted, so to speak, in the continuous monitoring of the position of an inner clock hand.
On the contrary, it seems to me that if there is a distinct primitive feeling of the passage of time, it is a feeling that has to be evoked. While you’re sitting, you are continuously feeling pressure on various parts of your body (though not always attending to those feelings); but I’m inclined to doubt that the feeling of passage works in that way. If so, then the difference between my experience five minutes ago, before I realized I’d been sitting three hours, and my experience now, does not consist merely in my attending to feelings of passage which were there all along. It arises only with the cessation or interruption of an activity.