<![CDATA[Abstrak :Kalender merupakan instrumen vital dalam kehidupan umat Islam, tidak hanya untuk kepentingan keagamaan tetapi juga sosial. Namun, ketidakterpaduan kriteria penentuan awal bulan Hijriyah menyebabkan perbedaan dalam pelaksanaan ibadah besar seperti Ramadan, Idul Fitri, dan Idul Adha. Artikel ini membahas landasan fikih serta berbagai model implementasi kalender Hijriyah global, termasuk Kalender Ummul Qura, Kalender Libya, hingga Kalender Global hasil Kongres Istanbul 2016. Penelitian ini menggunakan metode studi pustaka (library research) dengan pendekatan normatif-kualitatif. Data dikumpulkan melalui analisis literatur fikih klasik dan kontemporer, hasil-hasil kongres internasional, serta kajian astronomi Islam. Analisis dilakukan secara deskriptif-analitis untuk mengkaji argumentasi fikih dan astronomis dalam penyatuan kalender. Pendekatan fikih adaptif terhadap perkembangan astronomi menjadi kunci penting dalam penyusunan kalender unifikatif. Studi ini menunjukkan pentingnya kesepakatan ilmiah dan normatif dalam membangun Kalender Hijriyah Global sebagai upaya pemersatu umat Islam dunia.Kata kunci: Kalender Hijriyah Global, Hisab, Rukyat, Penyatuan Kalender, Fikih Islam Abstract : The calendar is a vital instrument in the lives of Muslims, not only for religious but also for social purposes. However, the disintegration of the criteria for determining the beginning of the Hijri month causes differences in the implementation of major worship such as Ramadan, Eid al-Fitr, and Eid al-Adha. This article discusses the foundations of fiqh and various models of implementation of the global Hijri calendar, including the Ummul Qura Calendar, the Libyan Calendar, and the Global Calendar resulting from the 2016 Istanbul Congress. This study uses a library research method with a normative-qualitative approach. Data were collected through the analysis of classical and contemporary jurisprudence literature, the results of international congresses, and the study of Islamic astronomy. The analysis was carried out in a descriptive-analytical manner to examine fiqh and astronomical arguments in the unification of the calendar. An adaptive fiqh approach to the development of astronomy is an important key in the preparation of a unifying calendar. This study shows the importance of scientific and normative agreement in building the Global Hijri Calendar as an effort to unite the world's Muslims.Keywords: Global Hijri Calendar, Hisab, Rukyat, Calendar Unification, Islamic Fiqh]]>
