Calculation and Transmission Practices in Ghurrah-Nāmes: A Comparative Evaluation Through an Example Attributed to Birgivī Mehmed Efendi and Hazret-i Bīcān

This study approaches the ghurrah-nāmes in Ottoman literature not merely as calendrical tables, but as a form of knowledge circulating among texts, tables, and computational practices. Accordingly, focusing on the ghurrah-nāme treatise found in a manuscript registered under the title Segür-nāme in the Afyon Gedik Ahmet PaşaProvincial Public Library, it examines how this form of knowledge was produced, organized, and reused. In the ghurrah-nāme treatise contained in the aforementionedmanuscript, the eight-year cyclical ghurrah-nāme system attributed to Birgivī Mehmed Efendi and the computational practice attributed to Hazret-i Bīcān areaddressed together as two distinct methods of calculation; moreover, the tables in the treatise are comparatively analyzed alongside the ghurrah-nāme table provided atthe beginning of the manuscript. This analysis reveals how the letter-based coding system and the cyclical conception of time used in ghurrah-nāmes operate within thetext, while also demonstrating that these structures could be reorganized across different historical layers. In this study, in order to evaluate the place of the analysis of the ghurrah-nāme treatise, which is central to the study, within the literature, manuscript examplesdated between the 16th and 19th centuries and identified through the keywords “ghurrah-nāme,” “ghurrah,” and “calendar” were also examined comparatively.The findings indicate that ghurrah-nāmes are part of a computational tradition that is reorganized, transmitted, and functionalized in different contexts, ratherthan being a fixed literary genre. Within this framework, the study addresses the function of ghurrah-nāmes within the Ottoman manuscript tradition and their relationship with calculation practices through a concrete case and comparative evaluation.