Commentary Purg XVI 25-27

The speaker can sense that the visitor is moving the smoke that he walks through and thus must be present in the flesh; for this reason, as he correctly assumes, the new arrival is still timebound.  The souls on the mountain have their own temporality, but one in which all of time is but a necessary prolegomenon to eternity, when real life begins for them.  Thus for them the months of the calendar are real but meaningless.