Marwadi and Labib, M. 2025. The Fiqh of Hisab Rukyat of Modernist Mass Organizations: A Study of Muhammadiyah and Al-Irsyad Al-Islamiyah Thought on the Hijri Calendar. International Journal of Social Science and Religion (IJSSR). 6, 3 (Nov. 2025), 391–406. DOI:https://doi.org/10.53639/ijssr.v6i3.377.