Tehran University of Medical Sciences International Journal of Occupational Hygiene 2008-5109 14 3 2025 08 30 171 179 Nafiseh Nasirzadeh Occupational Health Engineering, School of Public Health, Department of Occupational Health Engineering, Tehran University of Medical Sciences, Tehran Yahya Rasoulzadeh Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran Vahid Mirzai Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran Hossein Ostadhasanloo Curriculum, Department of Educational Science, University of Tabriz, Iran Aylar Nazari Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran Nahid Sani Department of Occupational Health Engineering, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran 2024 09 30 2024 11 18 Background: Executive cognitive functions are essential for functioning in dynamic environments. Moreover, they are directly influenced by work schedules and tend to decline over the course of a shift, resulting in an increased number of errors. Given that educational activities typically commence at fixed times, this study aimed to evaluate planning ability and working memory (WM) with temporal variations in college students. Methods: Forty-three participants were randomly selected from the occupational health and ergonomics students. WM and planning ability were assessed using the Wechsler Memory Scale (WMS) and Tower of London (TOL) test, respectively. The data were evaluated using SPSS version 16.0. Results: The mean scores of the TOL index were 31.46 and 31.42 in the morning and afternoon, respectively. The auditory working memory index was 7.54 and 7.7, whereas the visual working memory (VWM) index was 9.12 and 9.0 in the morning and afternoon, respectively. Planning ability and VWM were higher in the morning than in the afternoon. There was a relatively good correlation between median thinking times/the WMS index and the time of tests (p ≤ 0.05). Conclusion: Interestingly, the results showed no correlation between planning ability and WMS. Additionally, based on the findings, it is recommended to add courses requiring problem-solving and high-level focus to the morning curriculum. https://ijoh.tums.ac.ir/index.php/ijoh/article/view/644 https://ijoh.tums.ac.ir/index.php/ijoh/article/download/644/824