Background: The effects of circadian rhythm on stroke can include increases in morning heart rate, blood pressure, catecholamines, platelet aggregation, and hypercoagulability and might correlate with higher numbers of morning strokes. We assessed time of day and frequency of stroke code activation for a potential role of circadian rhythm in stroke risk. Methods: A retrospective analysis of prospectively collected data from an IRB approved stroke registry, from July 2004 to July 2020, was performed. Codes were included where stroke codes were activated with last known well (LKW) Results: A total of 5,366 subjects were identified. Stroke code activations differed across epochs (Night n=312, 5.81%; Morning n=1439, 26.82%; Afternoon n=2207, 41.13%; Evening n=1408, 26.24%: p Conclusions: This study found that most stroke code activations occur in Afternoons at this CSC. This may be due to patient level characteristics, bystander availability, or other factors. Future studies should assess multi-center data and include other circadian rhythm biomarkers.