Breakfast is quite normal, I mean, it may be a toast with marmalade, cereals and coffee, or maybe a croissant or a tortilla (Spanish, not the Mexican thing) pincho and a cofffee in a bar, but in any case something you would expect. Our lunch time is around 2pm, and it´s the largest meal of the day, consisting normally of a first, plus a second (meat, fish) and a dessert (quite often, fruit), and we take it easy (what you call "siesta" is one of the myths about Spain...we love our siestas in weekends, though). Some family run business close from 0130pm to maybe 4pm or even later, for a hearty lunch and some rest afterwards, but chain shops will remain open. 1 to 3 pm is the right time (well, maybe 1pm is too early yet in many places) for lunch and to relax, Spaniards like to take it easy during those times and if not at work, people like to stay home for the main news (3pm) and a siesta (if you´re aged and retired, it´s the best thing to do), but the rest go back to work. Dinner at homes ranges between 9pm to 10pm in most households, and in "normal" cities (I mean, those outside the tourist paths) restaurants start serving at 9pm (in some, the very earliest and you´ll only find foreigners there, is 8pm). Dinner is normally very light (either a soup, or an omelette, or some fish, or a salad) and takes less time than lunch. In any case, hard to see somebody with a sandwich on the street almost anywhere, we take lunch seriously. And dinner! The best option for lunch is the Menú del Día, Mo-Fr for lunch, for an unbeatable price you´ll have a first, a second, dessert, plus water, bread and wine.
