Well daylit public space, which ensures visual comfort, is one of the key design goals that architects and lighting designers seek. The public space such as airport's waiting hall is characterized by large dimensions which can get efficient daylighting levels from a skylight. In Cairo where the sunny and clear sky, improper skylight design can generate extensive heat gain and discomfort glare problems. This paper aims to study the effect of changing the vertical skylight pattern on the uniformity and availability of daylight in the public space of airport holding room. This investigation conducted through changing the shape of north oriented sawtooth opening from one rectangle opening shape to arched opening shape with multi-divisions. Generating the 3d models and analyzing the daylighting performance conducted through a parametric simulation approach. This approach included three software programs which are Grasshopper, Diva for Rhino and Evalglare. Simulations were conducted using the weather data file of Cairo, Egypt. The performance assessment was based on four metrics; IES approved method -Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE) -, Daylight Availability (DA) and Daylight Glare Probability (DGP). Results show that the different patterns of sawtooth arched opening in Cairo reached the required daylighting performance and achieved the acceptance criteria of the assessment metrics according to the daylighting requirements of LEED V4.