The word "tarde" is used here to describe both, what Britons call, afternoon and early evening. Most people learning Spanish usually thinks of tarde as translating directly as afternoon. When someone suggests to me that we meet in the tarde my years and years of British training kicks in and I think they mean sometime between three and five whilst they're visualising an early evening drink around eight or nine o'clock. Night starts about then, about nine, but again, it often depends on when you eat your evening meal.
We were watching some afternoon British TV yesterday. People who'd set up businesses in France and Spain were the focus. It's one of those programmes done as a sort of fly on the wall with commentary. In Spain a couple wanted to put Yurts on their land to complement their B&B business. They were waiting for the mayor to talk about planning permission. "He said he'd come in the morning," said the yurt owner, "It's already half past one so I don't suppose he's coming. This is Spain after all". I guffawed because it is, indeed, Spain and in Spain morning lasts till you've eaten lunch. As 2pm is the earliest that you might consider lunching then half past one is still, very much, morning. If someone greets you, at half two with the Spanish version of Good Morning then you know they haven't eaten yet.