The concept of the biological clock is crucial in understanding how both humans and cities operate within natural time cycles. Just like individual organisms have an internal mechanism regulating their biological functions, cities have a rhythmic pattern in human activity reflected in lighting, movement, and energy consumption. During Ramadan, the alteration in sleep and eating schedules creates a collective adjustment in human biological clocks, which in turn influences urban rhythms. This effect is significant enough to be detected from space.

NASA's interest in the biological clock of cities was piqued after observations made in 2012 when the Suomi NPP satellite began to capture unusual nighttime images of Cairo. These images indicated patterns that differed from typical urban behavior. The changes linked to Ramadan observed in Cairo illustrated how millions of individuals adjusting their daily rhythms can have a tangible impact on the entire city's operational tempo, making it notable for scientific investigations concerning urban life.

The implications of understanding these changes go beyond the urban environment; it can influence aspects like urban planning and energy management. Insights gained from analyzing how Ramadan alters the biological clock of a city could lead to better anticipatory strategies in managing resources during such peak periods, potentially offering expansive applications from public health to infrastructure development.