This is the reason why Spain changes times twice a year - La Provincia

The European Parliament has approved this Tuesday the initiative presented by the European Commission of end the change of seasonal time in the EU. With 410 votes in favor, 192 against and 51 abstentions, the MEPs have advocated delay the application of the measure until 2021, and not this year, as Brussels had originally planned. Until then and, as for 79 years, the last Sunday of March in Spain the clocks will be advanced one hour.

The measure was published for the first time in the Official State Gazette of March 8, 1940. It talks about the convenience of the national schedule marche according to that of other European countries and the temporary advance is justified with "the advantages of various orders" that it would bring. It was also reported in the BOE that "timely" would warn of the restoration of the normal time.

The warning never arrived. Until March 16, 1940 the Iberian Peninsula was governed by the time zone of the Greenwich meridian, but after the implementation of this measure was put on a par with the territories occupied by the Nazi German (GMT + 1). A) Yes, Spain, except the Canary Islands, continues to give the time according to the Central European Schedule and not the previous one, the Western, for which Great Britain and Portugal work.