good day

英 [ˌɡʊd ˈdeɪ]

美 [ˌɡʊd ˈdeɪ]

int. (白天见面或分手时用语)白天好，你(们)好，再见

牛津词典

exclamation

（白天见面或分手时用语）白天好，你（们）好，再见
used to say hello or goodbye politely when people first see each other or leave each other during the day
1. Good day to you.
  你好。

CONVENTION （问候用语，代替Hello及Goodbye）你（们）好，再见
People sometimes say 'Good day' instead of 'Hello' or 'Goodbye'.
1. Well, I'd better be off. Good day to you.
  好啦，我得走了，再见。

noun

We finally have a good day, grandma can enjoy several years of good luck.
咱们终于过上好日子了，奶奶也能享几年好福了。
Well, I'd better be off. Good day to you.
好啦，我得走了，再见。
Today is a good day for our barbecue.
今天对我们的烧烤是个好日子。
It's a good day for playing practical jokes on your friends.
这是一个对你的朋友们开实际玩笑的好日子。
Own good day should end immediately.
自己的好日子马上该结束了。
Have a good day.
有一个早晨好。
Good day to you, Bernard! It's a positive delight to see you
你好，伯纳德！见到你真高兴。
I'm sorry to complain so much. It's just not a good day.
我很抱歉发了这么多牢骚。今天可不是个好日子。
But you said it wasn't a good day.
但你说今天不是个好日子。
Today is a good day, the rain stopped;
今天是个好日子，大雨停了；