Abuelyamen, S.H. 2023. THE HIJIRI CALENDAR AND ITS CONFORMANCE WITH THE GREGORAIN CALENDAR BY MATHEMATICAL CALCULATIONS: 31st May 2022; 07th February 2023; 16th February 2023; 17th February 2023. MATTER: International Journal of Science and Technology. 9, (Mar. 2023), 01–19. DOI:https://doi.org/10.20319/mijst.2023.9.0119.