You are the only one who can calculate that length of time. The best way, in my opinion, to appreciate and understand the Sagrada Familia. It is advised to visit the Sagrada Familia at least twice: once during the day, when there are fewer tourists and you may enjoy some of the interior music, and once at night, when it is illuminated and has a unique atmosphere. When visiting Sagrada Familia during the day, you need make reservations your Sagrada Familia Tour in advance. because there are a limited number of tickets and they could be allocated for a specific time. Therefore, if you can, please make your reservation for a specified time frame. The Gua del Ocio y la Cultura by Turisme de Barcelona is the most comprehensive (and official) guide to Barcelona (Catalan Spanish). mobile app and book. Information is also included in this detailed manual about Park Guell Tour, although it focuses mostly on buildings, museums and organisations.