Computer method tells time according to person's body clock
US-based scientists have devised a computer method called 'ZeitZeiger' that uses blood samples to accurately predict circadian time, the time of day according to a person's body clock. ZeitZeiger used 15 genes from across human genome to predict body's internal time which, the scientists say, could be used to help diagnose and monitor sleep-related disorders and also to personalise treatments.