Portugal will switch to winter time on Sunday, October 25, with clocks being set back one hour throughout the national territory. On the mainland and Madeira, the change occurs at 2am, which becomes 1am, while in the Azores the adjustment takes place when clocks read 1am, returning to midnight. This change follows the European calendar, which provides for clocks to be moved forward on the last Sunday of March and set back on the last Sunday of October.
Despite the feeling that days become "shorter," setting the clock back does not reduce the duration of sunlight. What changes is the time at which sunrise and sunset are recorded: both occur one hour earlier on the clock. The gradual reduction in the period of daylight, typical of this time of year, is a phenomenon distinct from the time change, although both contribute to the perception of shorter afternoons.
The possibility of eliminating this practice was discussed in the European Union, but no definitive agreement was reached among Member States, so the system of two annual changes remains in place. The seasonal change was adopted with the purpose of making better use of available sunlight throughout the year, explains Santander bank, which notes that the practice dates back to the beginning of the 20th century and was implemented during the First World War as an energy-saving measure.
