Sure, but the point is that if you control for the effect of timezone displacement and just look at the sun, which is probably what originally shaped schedules in different human cultures, there's not that much difference between sleep and meal times in Spain and neighboring countries. Most of the perceived difference comes from the fact that a Spanish clock will be showing a later hour than most other countries when the sun is at a given point in the sky.
For example, I'm from Spain, and according to some quick searches, solar noon where I am today was at 13:47 (vs. 12:09 in New York, 12:14 in London, 12:20 in Berlin, 12:50 in Lisbon, 13:04 in Paris). So it's no wonder most Spanish people have lunch at around 14 (equivalent to eating at 12:22 in New York) and dinner past 21.
By the way, siesta culture is more of a stereotype than a real thing by now. I don't know anyone who regularly naps during the workweek (except kids and elderly). I guess it might still happen among physical workers in hot agricultural areas of the south, where you're not going to work the fields after noon under the scorching sun, but it's not a reality for the overwhelming majority of people.
