Hi Dr,

In fact, “Shang wu” means “late morning”. between 10-12

And zao shang means “early morning” between 6-10

Benny

Learn Chinese, Learn Mandarin from AskBenny

“Shàng(上)” is a preposition meaning “on top of” with an implication of “getting onto” or “arriving at” something, as “xià(下)” is a preposition for “under”, with an implication of “getting off” or “leaving from” something. In this way, we can observe the time phrases as a sort of linear concept, where all of the times of day are used to refer to the position of the sun. First, a breakdown into the different parts of the time phrases:
Zǎo(早)-early, beginning
Shàng(上)-getting onto
Zhōng(中)-middle
Wǔ(午)-noon(middle of the sky)
Xià(下)-getting off of
Wǎn(晚)-late, approaching an end
Now imagine the sky as a surface, as it probably appeared to the people creating the language, and the sun is a person or god “walking” across the sky.
“Zǎo Shàng(早上)” would therefore indicate the beginning of the sun’s arc across the sky, as the sun is “getting onto” the beginning of the arc of the sky.
“Shàng wǔ(上午)” is indicating that the sun is starting to “climb onto” the middle of the sky.
“Zhōng wǔ(中午)” is just saying that the sun is DIRECTLY in the middle of the sky.
“Xià wǔ(下午)” indicates the sun “getting off of” the middle of the sky, but still somewhat near it.
“Wǎn Shàng(晚上)” is saying that the sun’s journey is ending, and the sun is at the end of the arc, preparing to get off of it for the end of the day.

I hope this helped place the time phrases in a context that will be applicable to a multitude of scenarios, and give some insight into how the language developed. I find that thinking of Chinese in this way instead of just trying to remember the words makes it much easier to remember and learn.

柯炯然

(I am aware that I am posting this very late. The main purpose of my post is for people reading this from now on, though if it manages to help the person who originally posted the question, I will be very happy. ^_)

This is (reading it some years after it was posted!) not only a really helpful answer but also super interesting! Thanks for posting.