A retrospective cohort study of 683,809 people in England investigated the acute effects of daylight saving time changes on mental and physical health in 2008–2019. Health events such as anxiety, acute cardiovascular disease, depression, eating disorders, traffic accidents, self-harm, sleep disorders and psychiatric conditions in primary, secondary care and emergency settings were analysed. One week after the autumn clock change, events were reduced: anxiety from 17.3 to 16.7 (IRR 0.95; 95% CI 0.95–0.98), acute cardiovascular disease from 50.0 to 48.9 (IRR 0.98; 0.96–0.999), depression from 44.6 to 42.7 (IRR 0.96; 95% CI 0.96–0.99). 0.95–0.97), psychiatric conditions from 3.5 to 3.3 (IRR 0.94; 0.90–0.98) and sleep disorders from 5.4 to 4.9 (IRR 0.92; 0.87–0.97). No significant changes in the number of these events were found after the spring time change. The study used negative binomial regression models adjusted for day of the week, region and Easter weekend. Medical events were defined by the date recorded in electronic records, not necessarily the date of symptom onset.[3][6]