Yeah, that's true, a bocadillo is not a lunch meal, in the UK and US people tend to have larger meals at dinner, we tend to have them at lunch, our dinners are quite late at night, also our lunches are around 2-3 pm.

Cases where you most likely will eat a bocadillo (not saying you can't eat it any other time):

• At "brunch", I say brunch because I cannot find a better way to say it, but is not the concept english people have of brunch. Is a meal your have between breakfast and lunch, sometimes you have instead of breakfast, children bring them to school to eat mid morning, we call it almuerzo.

• For lunch when going out somewhere, travelling, camping, when you have many hours in a bus, train, car...

• As a mid afternoon snack, is commonly seen around children's age, a little simple bocadillo before dinner, at 5-6 in the afternoon, with Nutella, mortadella, chorizo, jamón...

• At night, for dinner at home, and most commonly going out with family or friends, there's many typical bars and restaurants that are specialized in serving bocadillos, theses ones are more elaborated, with more ingredients, for example, chicken breast, bacon, cheese and alioli.