劉歆《世經》既編排古史年代，又解釋《春秋》經傳，其曆術背景俱是三統。《漢書》〈五行志〉所載劉歆《春秋》日食說，也全以三統術立論。考察劉歆運用曆術解釋經傳的過程，知三統術與《春秋》經傳曆日並不吻合，但劉歆在《左傳》曆數與三統相異時，仍加引證；在經傳日食之期與三統推算結果不符時，逕改日食之期。此種特點，與東漢服虔以三統釋經傳有異。曆術與文獻的關係，既可為理解劉歆之學及兩漢經學史提供新的視角，也可為後世經學史的某些議題（如劉歆是否偽竄古文經傳）提供參照。總之，瞭解兩漢經學家的曆學，對於深入理解他們的經學，將大有助益。

Liu Xin's 劉歆 chronology of ancient history and analysis of the Spring and Autumn Annals 春秋 and its commentaries in his Shijing 世經 were based entirely on the Triple Concordance system, as was his theory of solar eclipses in the Annals recorded in the "Treatise on the Five Elements 五行志\" in the Book of Han 漢書. The process by which Liu Xin utilized this calendrical system shows that there are discrepancies between it and the Annals. He still cited the calendar as proof of dates of solar eclipses in the Zuo Commentary 左傳 even when the dates did not match; when such dates in the latter did not match up with those reckoned using the Triple Concordance system, he altered them to bring them into line. This differs from the way Fu Qian 服虔 approached the task in the Eastern Han. The relationship between calendrical system and written record can provide both a new perspective on understanding Liu Xin's scholarship and the study of the Classics during the Han, and an important reference for future discussions in the history of the study of the Classics (such as whether or not Liu Xin falsely altered them). In summary, understanding the calendrical studies made by Han scholars of the Classics will greatly assist in reaching a deeper understanding of their scholarship.