Good evening

In French and Italian, evening starts some time around when you get off work and finishes around 8 or 9. In Spanish, it's all tarde.

In French and Italian, the evening comes "late" - from the Latin serus, meaning "late". In Italian, they took the feminine, probably contracting from "hora sera" (late hour). In French, they took the masculine, but mangled it, as usual.

Unlike "morning" and "evening," French and Spanish really do make good use of "Good evening." Here we go:

Italian sera gives Buonasera (bwoh-na-say-rah).

French soir gives Bonsoir (bohn-swahr).

Spanish tarde continues to give Buenas tardes.

Incidentally, yes, soirée does mean "all evening," just like matinée means "all morning." A soirée is a party that fills up the whole evening, as opposed to either the dinner hour or the post-dinner hour.

And, if you were really wondering, tardus is Latin for "slow" (like a fire retardant slows the spread of flames) or "behind schedule". We're going to refrain from speculation about why the Spanish would so designate the time between lunch and dinner.