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Ultra-wide bandgap semiconductor materials have attained enormous attention from scientific community owing to their great potential in technological applications. The underestimated bandgap calculated from the standard density-functional theory (DFT) in the generalized gradient approximation (GGA), cannot predict the material properties accurately’ close to experiment. Herein, going beyond the DFT, we employ the more advance and accurate screened-hybrid functional DFT approach to evaluate the electronic and optical properties for monoclinic and trigonal phase of NaYO₂. Our calculated bandgap value for monoclinic phase is 5.4 eV with HSE06 functional match experimental value and depicts that previously theoretical value was underestimated. Optical properties with HSE06 functional show reduction in intensity along with significant blue shift from PBE-GGA. We validate the dynamic stability of both phases from negation of no negative frequency in phonon spectrum. Our calculations confirm NaYO₂ as large direct band gap that could be promising candidate for solar blind detector and environment technology.