Winter Time Begins: How the Clock Change Impacts Health in Portugal

On Sunday morning, mainland Portugal and the Madeira autonomous region set clocks back one hour at 02:00, while the Azores did so at 01:00, marking the end of daylight‑saving time and an earlier onset of darkness.

Health authorities note that the abrupt change disrupts the circadian rhythm, leading to up to a 30% reduction in total sleep time and poorer sleep quality. Studies link this period to a temporary spike in heart attacks, particularly among people over 50 and those with existing cardiovascular risk factors.

Experts advise minimizing blue‑light exposure before bedtime, eating dinner earlier, and engaging in light exercise to help the body adjust. Patients with chronic illnesses should consult their doctors to assess any heightened risks.