People in Saudi Arabia and the Gulf region are known for their preference of evening mingling and late-night trips, which may have negative effects on health. In this study, the main objectives were estimating the prevalence of daytime sleeping, and exploring the effect of sleep timing on memory strength. Whereas the specific objectives were assessment of the strength of memory of participants, and comparing the memory test scores between those who sleep at daytime and those who sleep at night. Online Google form was posted from July ? December 2018. It was consisted of three parts, and 10-item Rasch modeled memory self-efficacy scale was used to evaluate the memory strength. It was found that daytime sleepers were males more than females, older and married more than night sleepers. As will, daytime sleepers were less educated, less economic status, and had more family history of Alzheimer?s disease than night sleepers. Also, it was found that the prevailed reason among daytime sleepers was mainly due to work, followed by preferring night time. Furthermore, feeling lazy was more among people who sleep at night. These differences between the two groups were significant at 95% confidence interval. Moreover, it was found that score of memory test was higher amid night sleepers; nonetheless, the prevalence ratio between low versus med/high memory levels, among daytime and night sleepers was less than one. So it can be concluded that time of sleep does not associate with memory strength.