Analysis of the Government and Muhammadiyah's Determination of the Beginning of Ramadan and Eid Al-Fitr

Abstract

This study aims to analyze the determination of the beginning of Ramadan and Eid al-Fitr by the Indonesian government and Muhammadiyah from the perspectives of Islamic Law and Islamic Astronomy, as well as to examine the development of Muhammadiyah’s method from Wujudul Hilal to the Global Hijri Calendar (KHGT). This study employs a qualitative approach using library research. Data were obtained from the Qur’an, Hadith, official government documents, Muhammadiyah documents, Islamic astronomy literature, Islamic jurisprudence references, and relevant scientific articles. The data were analyzed descriptively, analytically, and comparatively by examining the legal foundations, methods, astronomical criteria, determination mechanisms, and social implications of each approach. The findings indicate that the government determines the beginning of the lunar month through the integration of hisab and rukyat within the isbat session, applying the MABIMS criteria of a minimum lunar altitude of 3° and elongation of 6.4°. Muhammadiyah historically applied Wujudul Hilal and subsequently developed KHGT, which promotes a global calendar based on the principle of one day, one date, using imkan al-rukyat criteria of 5° altitude and 8° elongation. These differences represent dynamic ijtihad influenced by religious texts, astronomy, and institutional authority. Calendar unification requires dialogue, scientific research, and mutual respect for diverse interpretations to ensure certainty in worship and strengthen Muslim unity.