A term used, with the correla-tive ad quern, (to which,) in expressing the computation of time, and also of distance in space. Thus, dies d quo, the day from which, and dies ad quern, the day to which, a period of time is computed. So, terminug d quo, the point or limit from which, and terminug ad quern, the point or limit to which, a distance or passage in space is reckoned