Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
Dining Times in Portugal
Portuguese dining schedules are later than in Northern Europe. Lunch is strictly between 13:00 and 14:30. Dinner restaurants often don't open until 19:30, and locals typically arrive around 20:30 or 21:00.
Trying to find a full kitchen open for dinner at 18:00 is difficult outside of tourist traps. If you are hungry early, look for a "Snack Bar" serving toasts or soup rather than a formal "Restaurante".