1. A Spanish greeting used in the afternoon and early evening (typically from noon until sunset or early night)
Good afternoon! How are you doing?
Boa tarde! Como você está?
2. The Spanish equivalent of the Portuguese 'boa tarde', used as a polite greeting during daylight hours transitioning into evening
I greeted my neighbor with 'buenas tardes' as the sun began to set
Cumprimentei minha vizinha com 'boa tarde' enquanto o sol começava a se pôr