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

Say I love you and Have a good day every morning.
每天早晨说我爱你和希望你今天过得开心。
Tell me about a good day.
和我说说那些美好的日子。
Saturday looks like a good day for a personal record.
周六看来是个创个人纪录的好日子。
A good day and the size and magnitude of the event leaves a lasting impression.
一个好的一天的规模和活动的规模留下了难以磨灭的印象。
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。
Well, I'd better be off. Good day to you.
好啦，我得走了，再见。
Today is a good day, the rain stopped;
今天是个好日子，大雨停了；
But you said it wasn't a good day.
但你说今天不是个好日子。
I've done a good day's work.
我已做了足足一天的工作。