Why is good evening and good night the same thing in spanish

Question

"Buenos Noches" =Good evening and Good night

Why is this?

Answer 1

How come we have "Good morning" in English, but no "Buenas mañanas" in Spanish?

Some things just are.

Answer 2

In English we have:

Morning - from 00:00 until 12:00 although if you are up after midnight you'd likely still use 'night' until it became light

Afternoon - from 12:00 until between ~16:00 and ~ 19:00, probably depending on light levels

Evening - from the end of the afternoon until between ~ 19:00 and 21:00

Night - from the end of the evening until 00:00

In Spanish we have:

Madrugada - from, I think, 00:00 until between ~ 04:00 and ~ 05:00

Mañana - from the end of the madrugada until 12:00

Tarde - from 12:00 until between ~ 19:00 and ~ 21:00

Noche - from the end of the tarde until 00:00

There is no equivalent word for evening, it is covered by both tarde and noche.

Also, 'good evening' is generally used as a greeting in English and 'good night' exclusively used as whatever you might call a departing salutation. Buenas tardes and buenas noches can be used as both a 'hello' and a 'goodbye'.