Despite nearly the entire main landmasses of both nations being contained between 7.5 degrees East and 7.5 degrees West, both France and Spain are offset +1 hour from the UK. What's the historical story behind this?
Before 1940 both France and Spain used the same Time zone as the United Kingdom (GMT). Following the Occupation by Germany France was forced to change its time zone to GMT+1 or Central European Time (which was the same as Germany and nearly all Territory occupied by Germany in Europe). In March 1940 the Spanish Government under Francisco Franco also changed their countries time zone to the defacto standard on the European Mainland. This decision was made due to the good relation between the facist Government in Spain and the Nationalsocialist Government in Germany. It made trade and communication easyer but was also an symbolic move towards Germany.
While often discussed in both Spain and France the changes made during the war where never reversed.