Daylight saving time
Daylight saving time (DST), also known as summer time, is a widely used system of adjusting the official local time forward, usually by one hour from its official standard time, for the spring, summer, and early autumn periods. This is a system carried out in 70 countries world wide, being Japan the only industrialized country that has still not been adapted to it.
Daylight saving time has as aim to reduce the global consume of energy, joining the beginning of the labor day with the hours of light.
The idea of DST was first put into practice by the German government during the First World War, to save oil. This situation was repeated in 1973, during the crisis of the petroleum, when most of the industrialized countries adopted the same system to face the complicated situation.
In Spain, this system was adopted since 1974, although the last regulation has arrived with the European directive 2000/84, which among other things it unifies the days in which the changes of hour in all the countries of the European Union take place, being these the last Sunday of March and October, respectively.