 The paper Blackburn and Jørgensen (2016b) uses hybrid tense logic to combine ideas of Prior with those of Hans Reichenbach on how to represent natural language tenses. Prior preferred the well-known tense operators described above, whereas Reichenbach preferred temporal references, that is, references to specific times, Reichenbach (1947). It turns out that the two approaches can be combined, which was not the route taken by Prior himself––see the account given in Blackburn and Jørgensen (2016b), 