The Calendar System in the Era of the Caliph Umar ibn al-Khattab (May Allah Be Pleased with Him)

Abstract

This research aims to study the emergence of the Hijri (Islamic lunar) calendar during the era of Caliph Umar ibn al-Khattab (may Allah be pleased with him), and to analyze the factors that led to adopting it as the official temporal system of the Islamic state. The study addresses the historical and political circumstances that made it necessary to establish a unified calendar system, as well as the reasons that resulted in choosing the Prophetic Hijrah (emigration) as the starting point of this calendar.The research also examines the role of the Hijri calendar in organizing religious affairs, such as determining the dates of fasting, Hajj (pilgrimage), and zakat (alms), and its impact on Islamic administration through regulating official correspondence and documenting contracts and financial transactions.The study shows that the Hijri calendar was not merely a tool for counting time, but rather an administrative and civilizational system that strengthened the identity of the Islamic state and contributed to its stability. It also becomes clear that this calendar system still retains its significance in the Islamic world up to the present day, indicating the depth of its historical and civilizational influence.Accordingly, the Hijri calendar is considered one of the prominent achievements that contributed to building the Islamic state and establishing its temporal systems across different eras.