The last few verses of the Hebrew book of Daniel are famously difficult. Among other issues, they present a duration problem that has long seemed intractable. But they also contain a key that provides a solution to the problem. That key is found in the lack of parallelism between the Aramaic expression of Dan 7:25b and the Hebrew expression of Dan 12:7b. The solution it allows is both accessible and expected. The author of Daniel created in his closing verses a mechanism to convey his view of the proper cultic calendar. That view places him securely among the other writers of early Jewish apocalypse and the authors of much of the sectarian and non-sectarian literature of the second century BCE. That mechanism and the solution it reveals are the subjects of this paper.