Damanhuri, A., Maskufa and Hadi, C. 2022. Determining Subuh Prayer Time Using GNU Octave To Find Polynomial Roots. Azimuth: Journal of Islamic Astronomy. 3, 1 (Feb. 2022), 16–26. DOI:https://doi.org/10.15642/azimuth.2022.3.1.16-26.