This work by St. Julian presents a theological discourse structured in three books, aimed at elucidating the timing of Christ's birth and the implications of biblical prophecy. The first book argues that Christ's birth was foretold in the Old Testament without specific year counts, while the second book explores apostolic doctrine that reveals the fullness of time for Christ's incarnation. The third book addresses the discrepancies in the reckoning of years between different biblical texts and emphasizes the importance of generations over years in understanding Christ's nativity. The author seeks forgiveness for any shortcomings in expression and appeals to a prince for support in defending the Christian faith.