Wrong title, it should be:
A Map of the world showing where the local time zone is wrong more than half hours
An hour is a human concept, we just divided the day to 24 parts, we could use whatever else division. Local time is correct only on the center longitude, which is a line with zero thickness.
Also it's clearly visible that France and Spain are in the wrong time zone, and it was changed by the Nazis. Before WW2 France and Spain was in the same zone as Britain. France changed because of the German occupation, and they forgot to change back after the war.