 Comrie (1985) and Gamut (1991) point out that this cannot be a complete account for temporal constructions that occur in natural languages. For instance the temporal profile of the sentence Sam would have worked cannot be analyzed by using a single reference time. This is one reason for the extended requirements for a formal theory of tense proposed by Comrie (1985: chapter 6). Furthermore,  Blackburn and Jørgensen (2016) combine the key insights of Prior  and Reichenbach in the framework of hybrid tense logic suggesting that  the two approaches are fully compatible with each other.