63 So then we have both a reason and a time for the resurrection: a reason because nature in all its produce remains consistent with itself, and does not fail in the generation of men alone; a time because all things are produced at the end of the year. For the seasons of the world consist of one year. What wonder if the year be one since the day is one. For on one day the Lord hired the labourers to work in the vineyard, when He said, “Why stand ye here all the day idle?”
Source: On the Death of Satyrus (New Advent)