It's not normal to work past 8pm in Spain. However, I know several people happily attending international meetings from home between 8-11pm because 8pm is the standard go to bed time for the kids.
What are the common business hours in Spain? I was thinking everything happens later there, so a 10 PM dinner is not uncommon, because of the ridiculous time zone they use (Central European Time, when most of the country is West of GMT).
Traditionally 9:00 to 18:00 with 1h lunch or 9:00 to 19:00 with 2h for lunch (a bit more old fashioned) in my experience.
In some companies you might start later and finish later.
Of course every company is different and some might insist on you being until very late there.