If you plan to do a lot of shopping, do your best to get it done by 1:30 in the afternoon before most of the stores throughout Spain shut down for lunch and siesta until they re-open around 4:30. This is the time of the day that I use to visit outdoor sites and monuments or for simply resting. A warning to light sleepers; bring earplugs as most hotel walls are generally quite thin.
If you are used to having your dinner around 6 PM, keep in mind that Spaniards start their dinner after 9 PM and most restaurants are closed after lunch until they re-open for the evening. The major department store of the country, El Corte Ingles, fortunately remains open during this time as do some souvenir shops. Don’t forget to ask for the Corte Ingles Tourist card that entitles you to a 10% discount on purchases made of 50 euros or more. All that is needed is your passport that you present at the customer service desk.