The intersection between religious belief systems and health-related practices has generated increasing academic interest in exploring parallels between ancient scriptures and contemporary scientific knowledge. This narrative review reappraises Qur’anic references to rhythmicity and the alternation of day and night through a chronobiological perspective. Modern chronobiology defines circadian rhythms as endogenous, near-24-h cycles that are synchronized primarily by environmental light via neuroendocrine pathways and regulate key physiological processes through hormonal outputs, most notably cortisol and melatonin. Disruption of these rhythms, referred to as chronodisruption, has been associated with adverse health outcomes. In the Qur’an, mentioned across multiple verses, the alternation of light and darkness and temporally specific human activities are presented as central to human functioning and reflection. These scriptural descriptions, when interpreted through a chronobiological lens, suggest an implicit recognition of rhythmic organization, particularly regarding the functional distinction between daytime and nighttime. We do not claim that the Qur’an describes circadian mechanisms, only that its presentation of day–night alternation is compatible with such understanding. Moreover, the practice of night prayer introduces a controlled and intentional modification of sleep-wake patterns, offering a potential model for investigating the physiological implications of brief and structured interruptions of circadian regularity.
Ach et al. (Sat,) studied this question.