Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Timings of human activities are marked by circadian clocks which in turn are entrained to different environmental signals. In an urban environment the presence of artificial lighting and various social cues tend to disrupt the natural entrainment with the sunlight. However, it is not completely understood to what extent this is the case. Here we exploit the large-scale data analysis techniques to study the mobile phone calling activity of people in large cities to infer the dynamics of urban daily rhythms. From the calling patterns of about 1,000,000 users spread over different cities but lying inside the same time-zone, we show that the onset and termination of the calling activity synchronizes with the east-west progression of the sun. We also find that the onset and termination of the calling activity of users follows a yearly dynamics, varying across seasons, and that its timings are entrained to solar midnight. Furthermore, we show that the average mid-sleep time of people living in urban areas depends on the age and gender of each cohort as a result of biological and social factors.

Original publication

DOI

10.1371/journal.pcbi.1005824

Type

Journal article

Journal

PLoS Comput Biol

Publication Date

11/2017

Volume

13

Keywords

Adult, Aged, Aged, 80 and over, Algorithms, Cell Phone, Circadian Clocks, Circadian Rhythm, Cities, Data Collection, Environment, Female, Human Activities, Humans, Light, Lighting, Male, Middle Aged, Movement, Probability, Seasons, Sleep, Temperature, Time Factors, Urban Population, Young Adult